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Accounts Receivable (Details) - USD ($)
Mar. 31, 2018
Dec. 31, 2017
Summary of accounts receivable    
Total gross receivables $ 1,456,638 $ 3,040,110
Less: allowance for doubtful accounts (27,006) (34,235)
Total net receivables 1,429,632 3,005,875
Block sales [Member]    
Summary of accounts receivable    
Total gross receivables 14,038
Construction services [Member]    
Summary of accounts receivable    
Total gross receivables 1,068,477 2,652,496
Retainage receivable [Member]    
Summary of accounts receivable    
Total gross receivables $ 388,161 $ 373,576