A Prototype of Concrete Hollow Blocks Using Recycled Crushed Concrete as Aggregates

This study proposes the design of a concrete hollow block using recycled crushed concrete as coarse aggregates. The critical objective of a mix design is to secure concrete which will provide the desired workability and the desired hardened concrete performance at the lowest practicable cost; thus the employment of recycled crushed concrete or RCC aggregates Prototype development under research and development has been used to manufacture desired results which lead to the conclusion that RCC's achieve the main objective of this study. Four different percentages of these recycled concrete aggregates consequentially chosen as 25%, 50%, 75%, and 100% shall be partially integrated with 3/8 inch coarse aggregates in respectively diminishing amounts in a constant mixing ratio in terms of the total weight of concrete. Upon curing for 7, 14, 21, and 28 days as per code standards, the fabricated prototypes shall be put to several testing procedures. In terms of strength, results reveal that the sample with 50% recycled crushed concrete is the most efficient for composite mix for non-load bearing CHB. Its strength for cylinder specimen is 2261 psi, approximately similar to that of blocks manufactured without any RCC. In terms of cost, CHB with 100% RCC turned out to have the smallest amount of P5.38 and is 18.24% cheaper than the CHB with no RCC. The cost of CHB with 50% RCC is P5.82 per piece.