Use of coconut shell as coarse aggregate in lightweight concrete

Wastes generated as a result of agricultural and industrial activities has become an environmental concern. In recent time global attention has been focused on environmental preservation, in an attempt to reduce environmental degradation, the use of agricultural and industrial wastes in concrete production has gained steady increase. Concrete being one of the major building materials that is used virtually in all aspects of construction, because it could be delivered to the job site, and be molded in situ or pre-cast to any form or shape. This makes it a material of choice in construction. This research work reports the investigation carried out to determine the use of coconut shell as an aggregate in light weight concrete. Concrete samples were produced with different mix ratios, to determine the best and economic proportions that will give acceptable compressive strengths. Concrete specimen were produced with coconut shell as coarse aggregate, ordinary river sand as fine aggregate and ordinary Portland cement as binders. Trial mixes which include (1:1:1, 1:1½:2, 1:2:2, 1:2½:3, 1:1½:3, 1:2:4, 1:2:3, 1:3:3, 1:3:4, 1:4:4) were done and it was observed that mix ratio 1:1:1 and 1:2:2 gave good consistency and workability with water cement ratio 0.5. The mix ratio 1:1:1; 1:2:2 gave compressive strength of 16N/mm2 and 7.71N/mm2 at 28day strength test respectively.