Pemanfaatan Crumb Rubber dan Fly Ash Sebagai Substitusi Agregat Halus dan Semen pada Ventilation Block

Along with infrastructure development which is growing rapidly in Indonesia, one of which is ventilation blocks which are widely applied in the construction of environmentally friendly houses. Ventilation blocks are non-structural concrete which functions as a partition with air circulation and lighting. However, increasing construction and industrial activities also have an impact on increasing residual materials, such as fly ash and crumb rubber (rubber powder). This research aims to create non-structural concrete innovations by utilizing residual materials so that the correct composition and proportions are known. The method used is an experimental method in the laboratory. This research produces test objects in the form of hollow bricks with output ventilation blocks in a square shape measuring 20 x 20 x 9 cm with a cement and sand mixture composition of 1: 6 and using 5 variations of test objects, namely for powder. rubber variety A, 0%; B, 5%; C, 7.5%; D, 10%; E, 12.5% of the weight of sand while for fly ash variation A, 0%; B, 5%; C, 10%; D, 15%; E, 20% of cement weight. The average compressive strength results for variations A = 3,699 MPa, B = 4,231 MPa, C = 4,356 MPa, D = 4,375 MPa, E = 3,799 MPa. For the average water absorption test results for variations A = 7.71%, B = 7.61%, C = 7.59%, D = 6.68% E= 6.64%. This research proves that this innovation has compressive strength and water absorption values that meet SNI specifications for quality III hollow concrete bricks. This ventilation block has the advantage of being lighter and having quite higher compressive strength than conventional ones.