Exploring the Barriers against Using Cryptocurrencies in Managing Construction Supply Chain Processes

Abstract

Various stakeholders are involved in managing supply chain processes in construction. Suppliers can hardly tolerate upfront costs when faced with flaws in the payment pipeline. This is a serious problem in building construction that uses a large variety of materials as opposed to civil construction that requires fewer types of materials. Alternative secure payment systems are needed, and the use of cryptocurrencies can be an option. However, cryptocurrencies are seldom used in building construction projects due to several challenges that are mostly ignored in the existing literature. To fill this gap, this study investigates the use of cryptocurrencies in construction supply chains as an alternative payment solution to improve the financial performance of the stakeholders by taking advantage of this economical and traceable financial transaction system. The study involves exploratory, descriptive, and empirical survey research. Accordingly, a literature review, focus group discussions, and statistical analyses (Friedman test, Wilcoxon test, and Mann–Whitney U test) were performed. The results imply that a lack of technical knowledge about cryptocurrencies, fluctuations in the value of cryptocurrencies, limited market opportunities, security gaps, personal information required by cryptocurrency systems, no assurance of permanent use, and government actions limiting the use of cryptocurrencies were the most significant barriers against using cryptocurrencies in construction supply chain management. The findings are expected to provide critical information to construction professionals and regulatory agencies about the potential advantages and shortcomings of cryptocurrencies, hence motivating policymakers to create strategies that minimize the concerns of construction professionals about using cryptocurrencies in the building construction industry.

1. Introduction

Payment problems such as delayed payments or non-payment are part of the inherent culture in the construction industry [1] and could exacerbate efficient supply chain practices [2], especially in the building construction industry that makes use of many different types of materials. Since payments and material delivery are linked to each other, blockage of the payment pipeline could affect all parties on the supply chains [3], which are characterized by many uncertainties [4]. Evidence suggests that the timing of the payments is a key element of the profitability and performance of construction firms [5]. However, the construction industry has long been regarded as having poor payment practices [6], eventually causing schedule delays [7], cost overruns [8], and disputes between stakeholders [9]. Additionally, the industry has a conditional payment settlement culture in that the contractor pays the material dealers only if or when paid by the construction owner, which can be considered to be quite distinctive compared to payments in other industries [1]. Particularly small and medium-sized enterprises (SMEs), such as material suppliers to construction contractors [10], can hardly tolerate upfront costs when faced with payment delays that cause severe fluctuations in their cash flow [11]. Improving payment performance in building construction projects may not only ensure stable and predictable cash flows for all parties on the supply chain, but may also increase the profitability of projects through better cost, time, and claim performance.

The literature on payment practices in the construction supply chain heavily focuses on the potential causes, effects, and solutions [1,12,13,14]. Several data-driven systems have been proposed to improve the performance of payment mechanisms in construction supply chains. These include the development of an information technology (IT) system to help select the most appropriate payment mechanism [15], the use of Markov chains to estimate the probability of being paid [16], and the adoption of cash flow control methods that estimate delays in owners’ payments [17]. Recent studies emphasize the need to integrate advanced technologies, mainly blockchain and smart contracts, to ensure the security of payments. For instance, Chong and Diamantopoulos [18] proposed an automatic payment system that includes the use of smart contracts, blockchain technology, and building information modeling after the completion of contractual obligations. By using the same technologies, Sigalov et al. [19] also proposed an automated payment-based contract administration mechanism to address late or non-payment issues. Similarly, Ahmadisheykhsarmast and Sonmez [20] developed a transparent, timely, and secure payment system for construction projects using smart contracts. The researchers mainly used fiat currencies in these studies and addressed several limitations of using cryptocurrencies for financial transactions such as a lack of regulations, lack of tax procedures, and extreme fluctuations in the value of cryptocurrencies [19,20]. Despite such barriers, the potential opportunities created by blockchain technology and smart contracts have been frequently investigated recently [21,22,23,24]. Nevertheless, it is noteworthy that the barriers against adopting cryptocurrencies and the related opinions of construction professionals have been generally overlooked in the literature. The use of cryptocurrencies could provide payment security in addition to ensuring product compliance and authenticity [25]. According to Ahmadisheykhsarmast and Sonmez [20], with the integration of cryptocurrencies into smart contracts, the insolvency of suppliers caused by cash-flow issues originating from late payments in construction projects can be prevented.

This study aims to identify and evaluate the barriers against using cryptocurrencies in construction supply chains and determine the opinions of construction professionals about this payment alternative. The contribution of the study is twofold. First, investigating and clearly stating the most significant barriers against adopting cryptocurrencies could provide guidance to professional/trade associations and government agencies in developing strategies for its use as an alternative payment option. Based on blockchain infrastructure, such a payment option can be integrated into smart contract and BIM technologies. On the other hand, the construction industry is known for being a slow mover in the adoption of new technologies. It is obvious that the opinions of professionals are always an important factor in the decision to use a new technology. Guidelines and regulations can be developed only by including the opinions of construction professionals. For that reason, understanding the opinions of construction professionals about the use of cryptocurrencies in construction supply chains is also a major objective of the study presented in this paper.

To achieve the objectives of the study, an exploratory research strategy was first pursued by means of a comprehensive literature survey. However, because the literature about the barriers against using cryptocurrencies in construction supply chains is rather limited, this was followed by a descriptive research strategy that involved a focus group discussion where (1) the barriers against using cryptocurrencies were classified into four categories, namely technical, trust, market, and regulatory; and (2) a questionnaire was prepared to seek the opinions of construction professionals about the use of cryptocurrencies in construction supply chains. Finally, an empirical research strategy was used to administer a survey to construction professionals and to analyze the data collected (i) to identify the most significant barriers; (ii) to conduct the Friedman and Wilcoxon tests to find whether the mean ranks of barriers in each barrier category are statistically different or not; and (iii) to perform the Mann–Whitney U test to examine differences in respondents’ opinions with respect to their expertise, knowledge of basic principles of economics, and experience in the use of cryptocurrencies. Overall, this study is expected to contribute to the literature about payment practices in construction supply chains, and in particular about the use of cryptocurrencies in this process. The impact is expected to be particularly pronounced in the building construction industry that involves a multitude of suppliers providing materials to the contractor.

2. Literature Review

Delayed payment to suppliers is one of the cultural features of the construction industry in most countries [2] and collaboration between suppliers and contractors is essential for successful project management [26]. Abdul Kadir et al. [27] highlighted that delays in payments to suppliers impact the timely delivery of materials, which in turn, causes a decline in construction productivity. Delayed payment and non-payment often result in conflicts and eventually legal disputes in the construction industry and exacerbate the difficulties encountered in the supply chain process [3]. Due to the integrated and dependent characteristics of the processes in the construction supply chain, the timing of the payments has a significant impact on the performance and sustainability of the payment processes [5]. A dispute between a contractor and a supplier can aggravate the smooth flow of payments and the smooth flow of material deliveries not only in a particular case, but also in other cases where the contractor is dealing with suppliers who were not even involved in the said dispute [28,29]. Chen [30] performed semi-structured interviews to explore the payment behavior of the parties to a construction project and found that the payment behavior of contractors relative to suppliers depends on the behavior of construction owners vis-a-vis contractors. Pettigrew [31] highlighted that the pay-when-paid and pay-if-paid culture in the construction industry creates serious problems between contractors and suppliers [32]. All these findings reported in the literature show the need for secure and timely payment procedures that eliminate the current cash flow problems experienced by suppliers and that establish a healthy and harmonious supply chain with no conflicts and disputes between the parties.

There has been a plethora of studies in the literature to address payment problems in construction supply chain management. In this context, Chen [33] investigated the cash-flow performance of contractors and evaluated the impacts of the payment models used by the owner on the cash flow of the contractor. Similarly, Andalib et al. [17] developed a cash flow estimation model to highlight possible delays in the payments received from the owner. The researchers created a budget realization index that is an indicator of the payment behavior of the owner and provided evidence for the applicability of the approach by using it in four case studies in Iran. To ensure a stable and predictable cash-flow for all supply chain parties, Motawa and Kaka [15] developed an IT system to help supply chain stakeholders to identify the most suitable payment mechanism. The researchers found that the proposed automated system satisfied the expectation of all supply chain parties. Tran and Carmichael [16] calculated the probability of timely payment after a claim, helping the sub-contractor to foresee potential cash-flow problems. Apart from cash-flow problems, some researchers focused on erratic payment patterns relative to relationship-based issues. In this context, Loosemore and Lim [34] examined organizational unfairness such as payment issues and supply chain exploitation in the Australian construction industry and found that procedural and distributive justice are low in the industry particularly related to sub-contractors and suppliers. Martin and Benson [35] investigated the quality of the relationship between subcontractors and contractors in construction supply chains and found that sub-contractors considered timely payment to be among the key factors in this relationship. Abidin and Ingirige [3] examined the opportunities to improve construction supply chains and discovered that delayed payments and non-payment cause serious disruptions in material delivery. Koc and Gurgun [36] performed a systematic literature review to extract stakeholder-associated life cycle risks in construction supply chains and found that late payment is among the critical risks and that supplier vulnerability has been overlooked in the literature. Morrison and Trushell [37] focused on the ownership of materials based on payment, delivery and contractual arrangements and addressed the need to develop a robust legal structure for materials located off site. Riazi et al. [38] investigated payment practices in an industrialized building system (IBS) project in Malaysia and found that poor payment mechanism is the major contributor to low IBS adoption. In addition to addressing payment-related issues directly, some researchers highlighted other aspects of supply chain management to improve the performance of construction projects such as sustainable supply chain management [39,40,41], robust supplier selection [42,43], supplying energy to green building projects [44], and more commonly, digitalization in supply chains [45,46,47].

Over the last couple of years, the use of blockchain-based technologies received considerable attention to solve several issues in construction supply chains. These studies included the examination of potential advantages and disadvantages of blockchain-based distributed ledger technologies (DLT) to improve supply chain management practices. For instance, Li and Kassem [48] conducted semi-structured interviews with industry professionals and recommended the enactment of new financial regulations to encourage the adoption of DLT in supply chain management. Similarly, Li et al. [49] performed a systematic literature survey about the practical use of blockchain technology in the built environment and pointed out that fluctuations in cryptocurrency valuations could be a challenge when cryptocurrencies are used in construction projects. Another study that addressed the potential advantages and the limitations of blockchain technology was performed by Nawari and Ravindran [50] who found that construction firms’ focus on return on investment, the complexity of construction projects, the poorly trained construction personnel, and the legal uncertainties constitute severe barriers against adopting digitalization. Likewise, Nanayakkara et al. [51] investigated the suitability of blockchain and smart contracts to solve payment problems in construction supply chains through an expert forum. The researchers found that these technologies can improve financial issues, payment issues, security of payments and ensure the legitimacy of long payment cycles in construction supply chains. In prefabrication supply chains, Bakhtiarizadeh et al. [52] emphasized the need for integrating blockchain and information management. They identified the channels required for effective information exchange between project parties using a questionnaire survey and found that blockchain technology has a positive impact on information management. Bayramova et al. [53] performed a scientometric analysis to explore the impacts of blockchain on supply chain resilience and recommended that regulators should identify and set basic standards for blockchain use. Albayati et al. [54] investigated the behavioral elements of the intentions of customers to use blockchain-based cryptocurrency transactions in supply chains other than construction supply chains. The researchers identified two powerful requirements that would encourage customer trust in blockchain-based cryptocurrencies: (1) regulatory support by the government, and (2) experience. On the other hand, Corbet et al. [55] conducted a systematic analysis of cryptocurrencies as financial assets, without focusing on a particular industry. The researchers found that legal, economic, and regulatory issues are major research gaps in this context.

Implementation of several technologies in supply chain management practices can help companies to enhance their competitive advantages in the sector [56]. However, supply chain practices have rarely benefited from the use of blockchain-based technologies, which is expected to increase in future [57]. Recently, some researchers have attempted to implement blockchain technology to improve supply chain practices in construction projects. For instance, Das et al. [58] presented a distributed blockchain-based framework and proposed an automated solution to initiate, validate, and execute interim payments in accordance with contract conditions. Tezel et al. [59] found that using blockchain technology to make payments is easier and more practical compared to other technologies in construction supply chain management such as tendering or project tokenization. By addressing the criticality of timely payments for the successful achievement of project objectives, Ahmadisheykhsarmast and Sonmez [20] proposed a smart contract system that automates the payment process and ensures secure payment between construction stakeholders. Likewise, Hamledari and Fischer [60] developed a model that integrates physical and financial assets in construction supply chains. They found that crypto assets have great potential to increase the integration between cash flows and product flows. Dakhli et al. [61] investigated the potential of using blockchain technology in the construction sector and found that blockchain implementation can result in an 8.3% cost saving in residential construction projects while Elghaish et al. [62] introduced a blockchain-based integrated project delivery framework for an automated financial system in construction projects and claimed that the proposed project delivery system was able to overcome many existing financial barriers.

This extensive literature review shows that payment issues in construction supply chains were investigated from a variety of perspectives and were directed to blockchain-based technologies. Most studies investigated the barriers or challenges encountered when using blockchain-based digital technologies but did not particularly focus on the use of cryptocurrencies by construction firms in their supply chains. In addition, there has been very few attempts to address the challenges encountered by construction professionals when using cryptocurrencies in construction supply chains, e.g., [19]. These facts imply that further exploration is necessary to understand the challenges, opportunities, barriers, benefits, and risks of using cryptocurrencies in construction supply chains and to ascertain the differences between the opinions of the professionals representing the construction industry. Government agencies and policymakers can safeguard project stakeholders against the risks of using cryptocurrencies, as the use of this method of payment becomes more widespread in the construction industry. This is particularly important for effective payment management in construction projects since the use of cryptocurrencies allows parties to pay each other without the traditional transaction formalities, expenses, and delays, hence improving supply chain management. In addition, examining the differences between the opinions of construction professionals who have different backgrounds (in terms of their profession, their knowledge of economic theories, and their experiences relative to using cryptocurrencies) can contribute to circumventing the barriers against using cryptocurrencies, hence generating competitive advantage in an industry where competitive pressures are high and the profit rate is low. Overall, this study is expected to fill the gap in the literature about cryptocurrency use in construction supply chains, and to inform government agencies in change of policymaking and construction professionals who manage construction projects about a new payment method (namely cryptocurrencies) that may allow them to improve current practices in supply chain management.

3. Research Methods

This study poses the following research questions:

• What are the most significant barriers affecting the use of cryptocurrencies in construction supply chains?
• Are the respondents’ opinions about the barriers significantly different from each other in each barrier category?
• Do the respondents’ opinions about the barriers differ according to their expertise, knowledge of basic principles of economics, and experience?

Based on the study of Chileshe et al. [63], these questions are answered by means of a three-stage research design that involves conducting an exploratory survey in the first stage, a descriptive survey in the second stage, and an empirical survey in the third stage, as presented in Figure 1. Exploratory survey research (Stage 1) involves a literature review leading to an initial list of barriers against adopting cryptocurrencies in construction supply chains. In the second stage, descriptive survey research is performed through a focus group discussion to refine the list of barriers since there has been limited research studies on cryptocurrency adoption in construction projects. Finally, in the third stage, empirical survey research is conducted through a questionnaire survey and the use of several statistical analysis techniques to determine the importance of the barriers as well as the opinion differences between the participants. According to Chileshe et al. [63], the use of this triangulated approach is most appropriate in conducting research studies related to construction management. Figure 2 shows the research flow of this study. As seen in Figure 2 and explained in later subsections, this study’s research strategy involves (1) determining the scope of the research, (2) collecting the data, and (3) analyzing the data. Accordingly, this study performed a literature survey followed by a focus group discussion to determine the barriers against adopting cryptocurrencies in construction supply chains (Step 1). Construction professionals were contacted to collect data about the barriers against using cryptocurrencies (Step 2). Finally, the collected data were analyzed by using several statistical tests (Step 3). These steps are described in detail in the following sub-sections.

3.1. Research Scope (Step 1)

This step involves exploratory and descriptive survey research. The exploratory survey research involved a comprehensive literature review that was conducted to identify the initial list of barriers affecting the widespread use of cryptocurrencies in construction supply chains. While reviewing the literature, studies that were not directly related to the construction industry were also investigated due to the scarcity of the cryptocurrency literature about the construction industry. The barriers so identified were then refined in a descriptive survey research that made use of a focus group discussion that was performed by seven professionals who had extensive experience in construction supply chains. The size of the discussion group was adequate as Ajayi and Oyedele [64] recommended between 5 to 25 participants for constructive discussion sessions. The motivation was to refine and classify the barriers affecting cryptocurrency use in construction supply chains identified in the prior literature survey. Participants were selected based on purposive sampling and thus a detailed background investigation was performed for each of them [36]. The participants were expected to comply with the following requirements: (i) having at least 15 years of experience in the construction industry, (ii) dealing with supply chain processes in construction for at least 5 years, and (iii) having experience in using cryptocurrencies at least once. Eighteen barriers were identified at the end of the group discussions and were classified into four categories: technical, trust, market, and regulatory (

Table 1. Barriers affecting the use of cryptocurrency in construction supply chains.

Barrier Category	ID	Barriers against Using Cryptocurrencies	ID	References
Technical barriers	Tc	Lack of technical knowledge about cryptocurrencies	Tc1	Priyadarshani [28]
		Possible changes in cryptocurrency protocols	Tc2	Al Yahya [65]
		Integration difficulties with other services	Tc3	Nawari and Ravindran [50]
		Irrevocable nature of cryptocurrency systems	Tc4	Perera et al. [66]
		Difficulties in converting cryptocurrencies to traditional currencies	Tc5	Bentov et al. [67]
Trust-related barriers	Tr	Security gaps due to vulnerable wallet passwords and malicious software	Tr1	Zeiringer and Thalmann [68]
		Low maturity of current cryptocurrency technologies	Tr2	Novak [69]
		Personal information required by cryptocurrency systems	Tr3	Perera et al. [66]
		Easy to commit fraud	Tr4	Perera et al. [66]
Market-related barriers	Mr	Fluctuations in the value of the cryptocurrency	Mr1	Kristoufek and Vosvrda [70]
		Limited market opportunities	Mr2	Nakano and Takahashi [71]
		Risky currency compared to traditional currencies	Mr3	Koblitz and Menezes [72]
		Doubts about the long-term viability of cryptocurrency systems	Mr4	Conrad et al. [73]
		Low adoption rate by SMEs	Mr5	Zhou et al. [74]
Regulatory barriers	Rg	No assurance of permanent use of cryptocurrencies in the long run	Rg1	Herbert and Litchfield [75]
		Governmental actions limiting or possibly forbidding the use of cryptocurrencies	Rg2	Koblitz and Menezes [72]
		Incompatibility of cryptocurrency systems with the current legal system	Rg3	Perera et al. [66]
		Possible use of cryptocurrencies in illegal activities	Rg4	Perera et al. [66]

).

3.2. Data Collection (Step 2)

A questionnaire survey was administered to professionals to collect their opinions about the use of cryptocurrencies in the construction supply chain. The survey consisted of two parts. In the first part, demographic characteristics and background knowledge were sought, while the importance of potential barriers against using cryptocurrencies were investigated in the second part using a five-point Likert scale (i.e., 1 = least important and 5 = extremely important). Even though some researchers adopted six-point [76] or seven-point Likert scales [77,78], a five-point Likert scale was adopted in this study due to its widespread use in surveys similar to the survey administered in this study [79,80,81]. The survey was sent to 357 construction professionals who were employed by Turkish contractors and whose attributes were in compliance with the aim of the study. These professionals were selected using random sampling [82]. A total of 306 responses were received out of which 284 responses were used in the study after screening the responses, providing a response rate of 80%. A variety of demographic characteristics such as age, gender, education level, expertise, position in the company, income level, experience, and knowledge of the basic principles of economic theories were sought in the first part [78,80,81] to investigate respondents’ differences in their opinion about each barrier. The respondents’ knowledge of the basic principles of economics was investigated with a question that asked whether the respondent had ever enrolled in at least one economics course during their undergraduate education or later in professional life.

A wide range of participants working in the construction industry were invited to participate in the survey. The distribution of the respondents’ professions is illustrated in Figure 3. Most of the respondents were either architects or engineers, and there were few participants who served in the health and safety, human resources, and legal departments of construction companies. Using this information, the respondents were categorized in two major groups “architects/engineers” and “others” for data analysis.

Table 2. Profile of the respondents.

Demographic Characteristics	Responses	N	%
Gender	Male	225	79.23
	Female	59	20.77
Age	20–30	20	7.04
	30–40	118	41.55
	40–50	82	28.87
	50 and higher	64	22.54
Education level	High school	14	4.93
	Bachelor	166	58.45
	MSc	89	31.34
	PhD	15	5.28
Income level (Turkish Lira)	2500 and lower	5	1.76
	2500–5000	44	15.49
	5000–10,000	94	33.10
	10,000–15,000	62	21.83
	15,000 and higher	79	27.82
Professional experience (years)	0–5	21	7.39
	6–15	116	40.85
	16–25	77	27.11
	26 and higher	70	24.65
Number of companies worked for	0–2	120	42.25
	2–5	120	42.25
	5–9	25	8.80
	10 and more	19	6.69
Approximate size of company (USD million)	50 and lower	108	38.03
	50–100	44	15.49
	100–500	63	22.18
	500 and higher	69	24.30
Number of times of online shopping per year	Never	6	2.11
	0–1	10	3.52
	1–3	33	11.62
	3–5	45	15.85
	5 and higher	190	66.90
Experience in use of cryptocurrency (years)	Never	214	75.35
	0–1	14	4.93
	1–3	29	10.21
	3–5	12	4.23
	5 and higher	15	5.28
Exposure to courses/training in economics	Yes	149	52.46
	No	135	47.54

shows participants’ other demographic characteristics. The majority of the respondents were male employees with 6–15 years of experience. Most of them were experienced in online shopping in their daily lives, which made them familiar with online payment transactions, and only a quarter of them used cryptocurrencies. Nearly half of the respondents attended economics courses during their college education or short courses during professional life.

3.3. Data Analysis (Step 3)

The collected Likert-type data were analyzed with non-parametric tests in the data analysis step. The use of non-parametric tests was most appropriate in this study since the intention was not to combine participants’ responses regarding survey items into a composite scale [83,84]. Non-parametric tests are also useful in eliminating the effects of the distribution-related assumptions made in parametric tests [85,86].

The data analysis step involved the use of the Statistical Package for Social Sciences (SPSS) 17.0 (i) to calculate the mean ranks of barriers against using cryptocurrencies in construction projects; (ii) to perform the Friedman and Wilcoxon tests [87] to determine whether the mean rank difference between barriers in each category is statistically significant; and (iii) to conduct the Mann–Whitney U test [88] to determine whether the respondents’ opinions changed because of their expertise, their knowledge of the basic principles of economics, and their experience with the use of cryptocurrencies. Since there were two groups to compare, the Mann–Whitney U test was used rather than the Kruskal–Wallis test, which is used to compare more than two groups [89].

The internal consistency of the collected data has to be assessed by using reliability analysis [90]. The Cronbach’s alpha (α) coefficient needs to be at least higher than 0.7, and higher than 0.9 indicates excellent reliability [91]. In this study, the Cronbach’s alpha coefficient of the 18 barriers was calculated as 0.914, indicating an excellent internal consistency, which means that the data could be used for further investigations.

The mean rank of the 18 barriers were calculated to determine the respondents’ opinions about the impacts of these barriers. The mean rank scores also revealed the importance of each barrier with respect to the others in each barrier category.

The Friedman test was performed to analyze the data in each barrier category. The Friedman test is a non-parametric test that is performed to determine the differences between three or more variables. It aims to identify whether at least two groups or categories present populations with different median values [85,92]. The required sample size should be higher than 30 in the Friedman test [93]. If the p-value is lower than 0.05, it means that there are significant differences between the barriers at a significance level of 5% [94]. In case of significant differences, the Wilcoxon can be run to determine the difference between the most important barrier and the other barriers in the corresponding category. Using this test, the most important and statistically significant barrier(s) in each barrier category were identified.

Finally, the Mann–Whitney U test was used to investigate the differences between respondents’ opinions relative to several features, including respondents’ (i) knowledge of the basic principles of economics, (ii) experience in the use of cryptocurrencies, and (iii) profession. The Mann–Whitney U test is a non-parametric test used when the data is not normally distributed, and the two samples are unequal in size [95]. It can be used for hypothesis testing between two independent samples with ordinal data [96], hence determining whether two independent groups represent two populations with different median values [95,96,97]. If the p-value is equal to or smaller than a predetermined level of significance (e.g., 0.05), then the difference between the two groups is statistically significant [98]. This test has been used commonly in the literature for similar research questions [88,98,99,100].

4. Results

Cryptocurrencies have the potential to bring advantages to financial transactions between supply chain partners in construction projects as an alternative payment protocol. Additionally, the use of cryptocurrencies may affect the performance of suppliers in particular, whose productivity rely mostly on regular payments. By integrating blockchain-based smart contracts and a cryptocurrency-based payment protocol, the transparency and trust among the parties involved in the supply chain could be improved, which in turn may increase the value generated during the supply chain process. However, many challenges still exist hindering the adoption of cryptocurrencies in construction supply chain management. Hence, this study surveyed construction professionals’ opinions about 18 barriers against using cryptocurrencies as a payment protocol in construction supply chains. Statistical analyses were used to address (i) the most significant barriers and (ii) the opinion differences between respondents. Unveiling the most significant barriers could enable the development of strategies to minimize the concerns of project stakeholders about the use of cryptocurrencies. Furthermore, the opinion differences between construction professionals can also help construction companies to develop strategies to improve their human resource that can add competitive advantage to them in the sector. The following sub-sections provide the results of this study in terms of the most significant barriers and opinion differences.

4.1. Most Significant Barriers against Using Cryptocurrencies

The findings of the statistical analyses are presented in

Table 3. Results of the Friedman test.

Barrier Category	Barrier against Using Cryptocurrencies	ID	Basic Statistics			Friedman Test			Wilcoxon Test
			Mean	St. Dev.	Mean Rank	Chi-Square	Degree of Freedom	p-Value	p-Value
Technical barriers						92.72	4	0.000
	* Lack of technical knowledge about cryptocurrencies	Tc1	3.711	1.071	3.56				-
	Possible changes in cryptocurrency protocols	Tc2	3.356	0.942	2.99				0.000 **
	Integration difficulties with other services	Tc3	3.349	0.922	2.96				0.000 **
	Irrevocable nature of cryptocurrency systems	Tc4	3.296	0.942	2.80				0.000 **
	Difficulties in converting cryptocurrencies to traditional currencies	Tc5	3.194	1.047	2.69				0.000 **
Trust-related barriers						26.01	3	0.000
	* Security gaps due to vulnerable wallet passwords and malicious software	Tr1	3.458	0.999	2.67				-
	Low maturity of current cryptocurrency technologies	Tr2	3.324	0.955	2.55				0.041 **
	Personal information required by cryptocurrency systems	Tr3	3.331	1.065	2.51				0.060
	Easy to commit fraud	Tr4	3.130	1.033	2.27				0.000 **
Market-related barriers						58.85	4	0.000
	* Fluctuations in the value of the cryptocurrency	Mr1	3.489	1.007	3.27				-
	Limited market opportunities	Mr2	3.472	0.967	3.24				0.534
	Risky currency compared to traditional currencies	Mr3	3.310	1.065	3.02				0.001 **
	Doubts about the long-term viability of cryptocurrency systems	Mr4	3.180	0.958	2.76				0.000 **
	Low adoption rate by SMEs	Mr5	3.074	1.127	2.70				0.000 **
Regulatory barriers						153.36	3	0.000
	* No assurance of permanent use of cryptocurrencies in the long run	Rg1	3.394	0.984	2.82				-
	Government actions limiting or possibly forbidding the use of cryptocurrencies	Rg2	3.356	0.982	2.72				0.419
	Incompatibility of cryptocurrency systems with the current legal system	Rg3	3.151	0.959	2.49				0.000 **
	Possible use of cryptocurrencies in illegal activities	Rg4	2.620	1.068	1.97				0.000 **

* The most significant barriers in each category according to the mean rank. ** The most significant barriers are statistically more important than these barriers at 0.05 level.

. Based on the Friedman tests performed for each barrier category (the three columns before the last column), statistically significant differences were observed in the ranking of barriers. It can therefore be stated that some of the barriers are more significant than others. To investigate the differences of the barriers in each category, the Wilcoxon test was conducted, and the results can also be seen in Table 3 (last column). The findings show that the most significant barriers in each category are:

• In the Technical Barriers category: a lack of technical knowledge about cryptocurrencies (Tc1).
• In the Trust-Related Barriers category: security gaps due to vulnerable wallet passwords and malicious software (Tr1) and personal information required by cryptocurrency systems (Tr3).
• In the Market-Related Barriers category: fluctuations in the value of the cryptocurrency (Mr1) and limited market opportunities (Mr2).
• In the Regulatory Barriers category: no assurance of permanent use of cryptocurrencies in the long run (Rg1) and government actions limiting or possibly forbidding the use of cryptocurrencies (Rg2).

4.2. Differences in Respondents’ Opinions about the Barriers against Using Cryptocurrencies

The differences in respondents’ opinions about the barriers against using cryptocurrencies were examined with respect to demographic features including (i) respondents’ knowledge of the basic principles of economics (yes or no), (ii) respondents’ experience in cryptocurrency use (yes or no), and (iii) respondents’ profession (architect/engineer or other).

The results of the Mann–Whitney U test with respect to the respondents’ knowledge about the basic principles of economics are shown in

Table 4. Results of Mann–Whitney U test based on respondents’ knowledge about the basic principles of economics.

Barrier Category	Barrier Against Using Cryptocurrencies	p-Value	Exposure to Courses/Training in Economics	Mean Score	Mean Rank
Technical barriers	Tc1—Lack of technical knowledge about cryptocurrencies	0.2806	Attended	3.745	147.21
			Not attended	3.674	137.30
	Tc2—Possible changes in cryptocurrency protocols	0.0016 *	Attended	3.537	156.11
			Not attended	3.156	127.47
	Tc3—Integration difficulties with other services	0.0424	Attended	3.436	151.29
			Not attended	3.252	132.80
	Tc4—Irrevocable nature of cryptocurrency systems	0.0212 *	Attended	3.409	152.33
			Not attended	3.170	131.66
	Tc5—Difficulties in converting cryptocurrencies to traditional currencies	0.2354	Attended	3.248	147.73
			Not attended	3.133	136.73
Trust-related barriers	Tr1—Security gaps due to vulnerable wallet passwords and malicious software	0.0083 *	Attended	3.611	154.12
			Not attended	3.289	129.68
	Tr2—Low maturity of current cryptocurrency technologies	0.0140 *	Attended	3.450	153.11
			Not attended	3.185	130.79
	Tr3—Personal information required by cryptocurrency systems	0.5534	Attended	3.356	145.13
			Not attended	3.304	139.60
	Tr4—Easy to commit fraud	0.0468 *	Attended	3.242	151.18
			Not attended	3.007	132.92
Market-related barriers	Mr1—Fluctuations in the value of the cryptocurrency	0.0176 *	Attended	3.604	152.95
			Not attended	3.363	130.97
	Mr2—Limited market opportunities	0.0655	Attended	3.557	150.56
			Not attended	3.378	133.60
	Mr3—Risky currency compared to traditional currencies	0.2533	Attended	3.362	147.56
			Not attended	3.252	136.92
	Mr4—Doubts about the long-term viability of cryptocurrency systems	0.0465 *	Attended	3.289	151.03
			Not attended	3.059	133.09
	Mr5—Low adoption rate by SMEs	0.0353 *	Attended	3.201	151.84
			Not attended	2.933	132.19
Regulatory barriers	Rg1—No assurance of permanent use of cryptocurrencies in the long run	0.1894	Attended	3.443	148.27
			Not attended	3.341	136.14
	Rg2—Government actions limiting or possibly prohibiting the use of cryptocurrencies	0.0002 *	Attended	3.530	158.78
			Not attended	3.163	124.53
	Rg3—Incompatibility of cryptocurrency systems with the current legal system	0.0008 *	Attended	3.322	157.04
			Not attended	2.963	126.46
	Rg4—Possible use of cryptocurrencies in illegal activities	0.1872	Attended	2.544	136.66
			Not attended	2.704	148.95

* Difference is statistically significant at 0.05 level.

. The findings imply that respondents’ opinions were statistically different at a significance level of 0.05 in 10 of the identified barriers. The results showed that the respondents who are knowledgeable about the basic principles of economics tended to consider the following barriers as more serious than the others: changes in the protocols (Tc2), the irrevocable nature of the cryptocurrency system (Tc4), security gaps (Tr1), low maturity of cryptocurrency technologies (Tr2), ease with which fraudulent activities can be performed (Tr4), fluctuations in the value of the cryptocurrency (Mr1), doubts about the long-term viability of the cryptocurrency systems (Mr4), low adoption rates by SDMEs (Mr5), governmental actions possibly forbidding the use of cryptocurrencies (Rg2), and incompatibility of cryptocurrency systems with the current legal system (Rg3).

The differences between the opinions of respondents who have used cryptocurrencies previously and those who did not are shown in

Table 5. The results of Mann–Whitney U test based on respondents’ experience in the use of cryptocurrencies.

Barrier Category	Barrier Against Using Cryptocurrencies	p-Value	Experience in Cryptocurrency Use	Mean Score	Mean Rank
Technical barriers	Tc1—Lack of technical knowledge about cryptocurrencies	0.0876	Experienced	3.886	156.20
			Inexperienced	3.654	138.02
	Tc2—Possible changes in cryptocurrency protocols	0.4708	Experienced	3.386	148.23
			Inexperienced	3.346	140.63
	Tc3—Integration difficulties with other services	0.6532	Experienced	3.271	138.93
			Inexperienced	3.374	143.67
	Tc4—Irrevocable nature of cryptocurrency systems	0.6032	Experienced	3.186	138.43
			Inexperienced	3.332	143.83
	Tc5—Difficulties in converting cryptocurrencies to traditional currencies	0.0555	Experienced	2.986	127.00
			Inexperienced	3.262	147.57
Trust-related barriers	Tr1—Security gaps due to vulnerable wallet passwords and malicious software	0.2212	Experienced	3.543	152.39
			Inexperienced	3.430	139.27
	Tr2—Low maturity of current cryptocurrency technologies	0.0023 *	Experienced	3.657	166.73
			Inexperienced	3.215	134.58
	Tr3—Personal information required by cryptocurrency systems	0.0844	Experienced	3.100	128.45
			Inexperienced	3.407	147.10
	Tr4—Easy to commit fraud	0.3294	Experienced	3.029	134.68
			Inexperienced	3.164	145.06
Market-related barriers	Mr1—Fluctuations in the value of the cryptocurrency	0.3861	Experienced	3.529	149.51
			Inexperienced	3.477	140.21
	Mr2—Limited market opportunities	0.0350 *	Experienced	3.643	159.46
			Inexperienced	3.416	136.95
	Mr3—Risky currency compared to traditional currencies	0.1674	Experienced	3.100	131.27
			Inexperienced	3.379	146.17
	Mr4—Doubts about the long-term viability of cryptocurrency systems	0.7582	Experienced	3.157	140.08
			Inexperienced	3.187	143.29
	Mr5—Low adoption rate by SMEs	0.0000 *	Experienced	3.786	195.92
			Inexperienced	2.841	125.03
Regulatory barriers	Rg1—No assurance of permanent use cryptocurrencies in the long run	0.4397	Experienced	3.271	136.26
			Inexperienced	3.435	144.54
	Rg2—Government actions limiting or possibly prohibiting the use of cryptocurrencies	0.0379 *	Experienced	3.471	159.21
			Inexperienced	3.318	137.03
	Rg3—Incompatibility of cryptocurrency systems with the current legal system	0.0787	Experienced	3.214	156.43
			Inexperienced	3.131	137.94
	Rg4—Possible use of cryptocurrencies in illegal activities	0.0000 *	Experienced	2.186	107.31
			Inexperienced	2.762	154.01

* Difference is statistically significant at 0.05 level.

. The findings indicate that respondents’ opinions were statistically different at a significance level of 0.05 in 5 of the barriers. Professionals who had prior experience in the use of cryptocurrencies tended to consider four of these five barriers as the most serious: low maturity of current cryptocurrency technologies (Tr2), limited market opportunities (Mr2), low adoption rate by small and medium size enterprises (Mr5), government actions limiting or possibly prohibiting cryptocurrency systems (Rg2), whereas they considered use of cryptocurrency in illegal activities (Rg4) to be less impactful.

It was reported in the literature that the respondents’ professional background could also impact the respondents’ opinions about the barriers against using cryptocurrencies in construction supply chain management. The results of the Mann–Whitney U test with respect to respondents’ professions are illustrated in

Table 6. Results of Mann–Whitney U test based on respondents’ profession.

Barrier Category	Barrier Against Using Cryptocurrencies	p-Value	Profession	Mean Score	Mean Rank
Technical barriers	Tc1—Lack of technical knowledge about cryptocurrencies	0.0053 *	Architect/engineer	3.570	132.71
			Other	3.952	159.20
	Tc2—Possible changes in cryptocurrency protocols	0.0147 *	Architect/engineer	3.246	134.01
			Other	3.543	156.97
	Tc3—Integration difficulties with other services	0.4441	Architect/engineer	3.302	139.84
			Other	3.429	147.04
	Tc4—Irrevocable nature of cryptocurrency systems	0.1533	Architect/engineer	3.240	137.60
			Other	3.390	150.85
	Tc5—Difficulties in converting cryptocurrencies to traditional currencies	0.6585	Architect/engineer	3.173	140.93
			Other	3.229	145.17
Trust-related barriers	Tr1—Security gaps due to vulnerable wallet passwords and malicious software	0.2068	Architect/engineer	3.397	138.03
			Other	3.562	150.12
	Tr2—Low maturity of current cryptocurrency technologies	0.0032 *	Architect/engineer	3.207	132.27
			Other	3.524	159.95
	Tr3—Personal information required by cryptocurrency systems	0.2962	Architect/engineer	3.279	138.77
			Other	3.419	148.85
	Tr4—Easy to commit fraud	0.1049	Architect/engineer	3.045	136.80
			Other	3.276	152.21
Market-related barriers	Mr1—Fluctuations in the value of the cryptocurrency	0.7892	Architect/engineer	3.464	141.55
			Other	3.533	144.11
	Mr2—Limited market opportunities	0.8978	Architect/engineer	3.464	142.05
			Other	3.486	143.27
	Mr3—Risky currency compared to traditional currencies	0.8643	Architect/engineer	3.296	141.89
			Other	3.333	143.54
	Mr4—Doubts about the long-term viability of cryptocurrency systems	0.1697	Architect/engineer	3.106	137.77
			Other	3.305	150.57
	Mr5—Low adoption rate by SMEs	0.0143 *	Architect/engineer	2.961	133.75
			Other	3.267	157.41
Regulatory barriers	Rg1—No assurance of permanent use of cryptocurrencies in the long run	0.7298	Architect/engineer	3.374	141.28
			Other	3.429	144.58
	Rg2—Government actions limiting or possibly prohibiting the use of cryptocurrencies	0.5049	Architect/engineer	3.335	140.15
			Other	3.390	146.51
	Rg3—Incompatibility of cryptocurrency systems with the current legal system	0.2984	Architect/engineer	3.106	138.89
			Other	3.229	148.65
	Rg4—Possible use of cryptocurrencies in illegal activities	0.9089	Architect/engineer	2.626	142.09
			Other	2.610	143.20

* Difference is statistically significant at 0.05 level.

. The findings show that respondents who were engineers or architects considered the following four barriers to be less serious when compared to non-engineers or non-architects: lack of technical knowledge (Tc1), possible changes in protocols (Tc2), low maturity of current cryptocurrency technologies (Tr2), and low adoption by SMEs (Mr5). The differences in the respondents’ opinions about these four barriers were statistically significant at 0.05 level.

A summary of the differences between the respondents’ opinions with respect to three demographic features is illustrated in

Table 7. Summary of the differences in respondents’ opinions about the barriers against using cryptocurrencies.

Barrier Category	Barrier Against Using Cryptocurrencies	Respondent is Knowledgeable about the Basic Principles of Economics	Respondent is Experienced in the Use of Cryptocurrencies	Respondent is not an Engineer nor an Architect
Technical barriers	Tc1—Lack of technical knowledge about cryptocurrencies	X	X	+√
	Tc2—Possible changes in cryptocurrency protocols	+√	X	+√
	Tc3—Integration difficulties with other services	X	X	X
	Tc4—Irrevocable nature of cryptocurrency systems	+√	X	X
	Tc5—Difficulties in converting cryptocurrencies to traditional currencies	X	X	X
Trust-related barriers	Tr1—Security gaps due to vulnerable wallet passwords and malicious software	+√	X	X
	Tr2—Low maturity of current cryptocurrency technologies	+√	+√	+√
	Tr3—Personal information required by cryptocurrency systems	X	X	X
	Tr4—Easy to commit fraud	+√	X	X
Market-related barriers	Mr1—Fluctuations in the value of the cryptocurrency	+√	X	X
	Mr2—Limited market opportunities	X	+√	X
	Mr3—Risky currency compared to traditional currencies	X	X	X
	Mr4—Doubts about the long-term viability of cryptocurrency systems	+√	X	X
	Mr5—Low adoption rate by SMEs	+√	+√	+√
Regulatory barriers	Rg1—No assurance for permanent use of cryptocurrencies in the long run	X	X	X
	Rg2—Government actions limiting or possibly prohibiting the use of cryptocurrencies	+√	+√	X
	Rg3—Incompatibility of cryptocurrency systems with the current legal system	+√	X	X
	Rg4—Possible use of cryptocurrencies in illegal activities	X	−√	X

Notes: A positive check mark (+√) indicates that the barrier is more impactful, whereas a negative check mark (−√) indicates that the barrier is less impactful. A cross mark (x) indicates that there is no statistically significant difference between the opinions of the respondents in the two groups. Difference is statistically significant at 0.05 level.

. The findings show that integration deficiencies with other services (Tc3), difficulties in converting blockchain-based cryptocurrencies to traditional currencies (Tc5), requirement of personal information (Tr3), risky currency compared to other currencies (Mr3), and not providing guarantee for permanent use (Rg1) were not considered by any participant groups considered in this part of the study to be more important barriers than others. It is not surprising that none of these barriers were found among the top barriers according to the mean rank scores (Table 3). Table 7 also shows that the opinions of respondents who are knowledgeable about the basic principles of economics, who had prior experience in the use of cryptocurrencies, and who are not engineers or architects (such as finance experts, accountants, and information technology professionals) had similar views about low maturity of current cryptocurrency technologies (Tr2) and low adoption rate by SMEs (Mr5). It is not surprising to see that engineers and architects are not as informed about blockchain technologies and cryptocurrencies as are finance, accounting, and IT professionals.

5. Discussion

This study evaluates the barriers against adopting cryptocurrencies in construction supply chains as an alternative payment structure. The findings of this study highlighted the lack of technical knowledge, security related issues, price fluctuations, market opportunities, governmental actions, and legal procedures.

Past studies mostly focus on the general use of blockchain technologies. For instance, Cheng et al. [101] performed a systematic literature review to identify the benefits and challenges of blockchain technologies and concluded that information security and trust are among the major challenges faced by stakeholders in implementing blockchain in construction supply chain management. Overall, the researchers identified significant challenges in construction such as data security, scalability, technical integration, expertise, installation cost, organizational complexity, characteristic of the construction, regulation issues, and social acceptance. A similar study was also performed by Xu et al. [21] who found that a lack of IT infrastructure, uncertainty in legal regulations, and project complexities are the root barriers in the architecture, engineering, and construction (AEC) industry. Nawari and Ravindran [50] investigated the potentials and limitations of using blockchain technology in the built environment with a particular focus on integrating blockchain with BIM. The researchers found that inadequate education at company level, privacy, risk allocation, and responsibility assignment were the significant barriers. Nanayakkara et al. [51] performed a literature survey to compare blockchain technology with existing information systems in construction supply chains and highlighted that blockchain and smart contracts can present limitations related to recoverability, scalability, modifiability, maturity, complexity, and developability compared to conventional approaches. Tezel et al. [59] examined the applications of blockchain-based models in construction supply chains through focus group discussion sessions. Overall, the feedback provided by the participants highlighted that cultural resistance (as opposed to automated payment), issues related to fluctuations of the value of tokens, and necessity of integrating clients’ accounting, ID systems and existing contracts were elaborated as significant issues when implementing blockchain. In addition to the studies directly related to the AEC industry, Ghosh et al. [102] examined the security of cryptocurrencies and highlighted several challenges in its adoption such as usability, security, privacy, versioning, size, wasted resource, latency, and throughput.

5.1. Evaluation of the Barriers against Using Cryptocurrencies

The following paragraphs discuss the most significant barriers in the barrier categories defined earlier in this paper, namely technical, trust-related, market-related, and regulatory barriers.

Technical Barriers Category: It was highlighted by Chowdhury et al. [103] that professionals’ lack of understanding of cryptocurrencies is one of the most significant barriers for technology adoption in construction projects. It is also noted by Qammaz and AlMaian [104] that personnel’s inadequate technical knowledge could lead to ineffective risk management practices, which is particularly important when new procedures are adopted [105]. These assertions are supported by the findings in this study that show that lack of technical knowledge about cryptocurrencies (Tc1) is indeed the most significant barrier in the Technical Barriers category. The construction industry is known to be a slow adopter of emerging technologies and tools [106]. With advances in digitalization and potential applications of blockchain technology in the industry, construction companies should employ staff who are familiar with contemporary developments and tools [107]. The know-how transferred to the organization by these employees can bring momentum in the adoption of several recent technologies including the use of cryptocurrencies as a payment protocol.

Trust-Related Barriers Category: The respondents evaluated security gaps due to wallet passwords and malicious software (Tr1) and personal information required by cryptocurrency systems (Tr3) as serious barriers against using cryptocurrencies in trust-related barriers, both barriers related to the security concerns of potential users. Despite the fact that the security of cryptocurrencies is considered to be very strong as it is based on a chain of cryptographic puzzles, there are still some security concerns reported by users who are uncomfortable because cryptocurrencies are fully digital currencies that have no physical existence [108]. Viruses, keystroke loggers, or malware could leave wallets unprotected [109]. Bushager et al. [110] examined the security and privacy of Bitcoin and found that hardware failure, software failure, self-induced events, and malicious events were the most frequent reasons for Bitcoin key loss. Although cryptocurrencies’ security, speed, and not requiring intermediaries can facilitate international transactions, the extent of fraudulent and criminal activities cannot be ignored, limiting cryptocurrencies’ widespread use [111]. In this respect, a cryptocurrency regulation is being developed in the U.S., which will prevent tax evasion, abate crime, and make cryptocurrencies a secure vehicle for investment [112]. In addition to the U.S., there are other crypto-friendly countries such as Canada considering crypto transactions as business income, Australia accepting cryptocurrencies for capital gains tax purposes, and El Salvador which is the only country that allows cryptocurrencies as legal tender [113]. These uncoordinated developments can limit cryptocurrencies’ use in international contracts. This is particularly important for construction projects since many construction companies are involved in several projects across the world and need speed, stability, and certainty in cross-border financial transactions [114].

Market-Related Barriers Category: The results of Wilcoxon tests also showed that fluctuations in the value of the cryptocurrency (Mr1) and limited market opportunities (Mr2) are the most significant market-related barriers. The regular occurrence of tremendous price fluctuations in the value of cryptocurrencies [115] is not rare. These serious fluctuations in the value of tokens are expected to complicate cryptocurrency use [59], to be a major barrier against transactions in cryptocurrencies, and to contribute to the limited use of cryptocurrencies in the construction supply chain. Speculative activities in the cryptocurrency market are particularly conducive to volatility and uncertainty, which in turn result in reducing the efficacy of cryptocurrencies [116]. It is likely that one of the reasons why construction professionals would hesitate using cryptocurrencies is to protect their company against fluctuations in the value of cryptocurrencies.

Regulatory Barriers Category: In the category investigating the regulatory barriers, no assurance of permanent use of cryptocurrencies in the long run (Rg1) and government actions limiting or possibly forbidding the use of cryptocurrencies (Rg2) were determined as the most significant barriers. Several restricting regulations over the use of cryptocurrencies were issued in different countries. For example, a crackdown on Bitcoin in China led to a sharp decline in the price of Bitcoin and other cryptocurrencies by as much as 30% [117], and the Central Bank of China announced all cryptocurrency transactions are illegal in the country [118]. In Turkey, according to a recent regulation, crypto assets cannot be used directly or indirectly for payments [119]. A recent report of the European Securities and Markets Authority (ESMA) [120] drew attention to the risks involved in crypto-asset investments since crypto-assets are characterized by extreme price volatility. The report also pointed out that most trading platforms are unregulated and are prone to manipulation and operational flaws. Such reports and restrictions can slow down or limit the adoption of cryptocurrencies in business transactions as an alternative payment method, despite the sizeable reduction of transaction costs particularly in international transactions. The decentralized nature of the technology compels central banks and governments to issue restrictive national and international regulations. Therefore, a robust legal framework, can provide market confidence and new opportunities to diversify a company’s portfolio [116]. An appropriate legal framework can provide a reliable financial environment for stakeholders and endorse the use of cryptocurrencies as an alternative solution to chronic payment problems in the construction supply chain.

Overall, cryptocurrencies are digital currencies based on blockchain technology and can contribute to digitalization in several processes. For instance, having change, time, and fraud-resistant records of data with the help of blockchain technology can address some of the adoption issues of building information modeling (BIM). The use of cryptocurrency in the procurement system increases the security of transactions and payments made by a company and supports the implementation of BIM in a more confident way [19]. The integrated use of cryptocurrencies with smart contracts ensures the formation of an unchallengeable record of cost and payment, which can be implemented in 5D BIM that includes cost estimation and analysis [121]. Transactions can be recorded and tracked by project stakeholders in a distributed manner, improving traceability and trust within the project environment. However, a construction supply chain that is digitalized with cryptocurrencies requires that the many stakeholders in the supply chain (i.e., contractors and their material dealers) adopt cryptocurrencies to perform construction activities [23]. Therefore, inter-stakeholder solutions need to be sought in addition to mutually agreeable regulations for a sustainable and reliable cryptocurrency-based payment mechanism.

5.2. Opinion Differences between Respondents

Considering that blockchain technology is interlinked with basic economic systems [122], it is not surprising to see that respondents who were exposed to basic economic principles through economics courses/training would expect these 10 barriers to be taken seriously by professionals in the construction industry. Presthus and O’Malley [123] performed a survey on Bitcoin adoption and found that people mostly used cryptocurrencies due to technological curiosity. Thus, construction professionals who wish to experiment with cryptocurrency systems, should acquire a good knowledge of the basic principles of economics and should be prepared to overcome the 10 barriers identified in this analysis.

Considering the respondents’ strong opinions about the low maturity of cryptocurrency systems, the limited market opportunities, the low adoption rates by small and medium size companies, and the uncertain future of cryptocurrency systems, professionals who have been exposed to the use of cryptocurrencies in the past might consider cryptocurrencies to be more suitable for personal and largely speculative investments rather than professional use risking the survival and growth of a company just as Penzes et al. [11] state. Their fear of governmental actions limiting or possibly prohibiting cryptocurrencies may very well have developed during their exposure to the cryptocurrency environment in the past, as were their opinions about the market conditions, the maturity and uncertainty associated with cryptocurrencies, and the lack of legal protections. It is somewhat intriguing that respondents with prior experience with cryptocurrencies minimized the dangers of using this currency system for illegal activities. Nevertheless, an opinion informed with cryptocurrency practices has value and should receive special attention by construction professionals who are planning to be future users of cryptocurrencies.

The results might indicate that construction professionals, who are generally engineers or architects, can underestimate the potential impact of many barriers against using cryptocurrencies very much like they underestimate the importance of technical advances as evidenced in Yaşar et al.’s [124] work. On the other hand, it should be noted that in an early study, Zhou et al. [74] found that payments made with a cryptocurrency protocol in small and medium size enterprises do create transaction difficulties for these companies’ management.

6. Managerial Insights

Cryptocurrencies were introduced as a new electronic payment protocol based on blockchain technology, which allows the exchange of assets digitally in a decentralized system with lower transaction costs and improved traceability of the entire transaction history. Their emergence, development, and proliferation are a typical part of Industry 4.0, supporting industrial connectivity and smart automation. These features pledge several advantages, yet there are still challenges in their adoption as an alternative to conventional payment methods.

Inherent in their nature, construction projects involve different types of risky processes associated with many stakeholders that require proper management and coordination practices. Supply chain management is one of the important processes in the life cycle of especially building construction projects, which mostly operate on conventional approaches. As a slow adopter of recent technologies, construction professionals mostly prefer using well established methods and technologies rather than relying on novel and innovative practices. Employing professionals who can evaluate and appreciate the pros and cons of the adoption of recent technologies such as cryptocurrencies as an alternative payment protocol in supply chain management would be useful. As digitalization of many processes is becoming widespread in the construction industry, employing such qualified professionals would provide a competitive advantage to companies operating in the construction market. On the other hand, the legal challenges, that potential users of cryptocurrencies may face require proper regulations to provide confidence and stability to the potential adopters of this technology. This becomes even more critical in international transactions that are very common in the building construction supply chain. Overcoming at least the most important barriers identified in this study may persuade construction professionals to use cryptocurrencies in supply chain management and to integrate this advanced payment process with other recent technologies such as smart contracts and BIM.

Further investigations related to the professionals’ opinions revealed the following results:

• The respondents who are not familiar with the basic principles of economic theory and practice are less concerned about the use of cryptocurrencies. The respondents who are familiar with the basic principles of economics, tend to be concerned about the potential barriers, such as changes in cryptocurrency protocols, security gaps caused by vulnerable wallet passwords and malicious software, government actions that could limit and possibly prohibit the use of cryptocurrencies, and the incompatibility of cryptocurrency systems with the current legal system. Therefore, employers’, consulting economists’, and legal experts’ fundamental knowledge of economics can be instrumental in acknowledging the pros and cons of adopting cryptocurrencies in construction supply chain management and in mitigating the adverse implications of cryptocurrencies in transactional activities in the construction industry.
• Respondents who had experienced using cryptocurrencies felt more threatened by market-related and regulatory concerns than respondents with no prior exposure to cryptocurrencies. This can be related to the awareness of these respondents about the developments in the economic and legal domains. Since rapid value changes and severe fluctuations are common in the cryptocurrency market, central banks and governments issue regulations and the legislature enacts laws frequently, which might affect the implementations in the transactional processes. Professionals who are familiar with cryptocurrencies and who follow the associated national and international developments can be useful assets in a construction organization, if such a payment protocol is adopted in the supply chain processes.
• Respondents in the engineering and architecture professions were less concerned about the use of cryptocurrencies than other professionals. This tendency may hinder the development of adequate risk mitigation measures to minimize the potential concerns highlighted by others. Advances in technology are inevitable and continuous and may have different impacts depending on the activity, the industry, and the economic environment. Construction professionals generally tend to focus on technical issues and try to resolve them using conventional methods and tools. On the other hand, modern technologies that are recently developed are finding their ways into construction projects. Analyzing the issues encountered in construction supply chains is one of the most investigated topics in the construction management literature. Construction professionals’ exposure to non-technical aspects of construction projects, secure transaction processes between contractors and suppliers, stable market value of cryptocurrencies and demand for construction, and a good understanding of government policies concerning the transactions between contractors and suppliers could contribute to improved construction supply chain processes.

7. Conclusions

Construction companies and suppliers are frequently faced with payment-related issues, which adversely impact the performance of the supply chain especially in building construction. Flawless material delivery and prompt payment are important to sustain efficient supply chain practices, and yet delayed payment or non-payment is a cultural reality in the construction industry. This study aimed to explore the challenges and barriers against using cryptocurrencies as an emerging payment protocol in construction supply chain management. The most significant barriers in each category were identified through a literature review and refined in a focus group discussion. Then, the Friedman and Wilcoxon tests were performed to observe the differences in the ranking of the categories and the barriers. Finally, the Mann–Whitney U test was performed to examine and understand the differences in the respondents’ opinions with respect to their expertise, their knowledge about the basic principles of economics, and their experience in the use of cryptocurrencies.

The findings imply that the lack of technical knowledge about cryptocurrencies, fluctuations in the value of cryptocurrencies, limited market opportunities, security gaps due to vulnerable wallet passwords and malicious software, requiring users to provide identifiable information, no assurance of permanent use of cryptocurrencies in the long run, and government actions limiting or forbidding the use of cryptocurrencies were the most important barriers against using cryptocurrencies in construction supply chain management. This study also investigated the differences in construction professionals’ opinions based on the characteristics of the respondents. For example, significant differences were detected between respondents with or without solid knowledge about the basic principles of economics; between respondents with or without experience in the use of cryptocurrencies; and between respondents who are engineers/architects or practicing other professions.

Overall, this study involves an exploratory investigation related to the adoption of cryptocurrencies in supply chain processes in construction projects. Identifying and understanding the potential barriers against using cryptocurrencies in supply chain management may make it easier to overcome these barriers and encourage construction professionals to consider adopting cryptocurrencies as an alternative solution to chronic payment problems encountered in the construction supply chain of especially building construction projects. Being one of the first attempts in the literature to explore the adoption of cryptocurrencies in construction supply chains, this study opens the way to using cryptocurrencies in financial transactions between contractors and suppliers in construction projects. Further studies can be conducted to find out the ways of integrating cryptocurrencies in contracts and evaluating stakeholders’ perspectives.