Mechanical properties of reclaimed plastic concrete

The objective of the study was to obtain the compressive, tensile and flexural strengths, thermal resistance, chemical resistance and fire resistance of the reclaimed plastic concrete in order to investigate the feasibility as a new construction material. This reclaimed plastic concrete is a compositive material which is composed of sand and blend of 50% of LDPE (Low density polyethylene) and 50% of HDPE (High density polyethylene) which are inexpensive and easy to reclaim. As the binder content ranging from 20 to 40% increased, the compressive, the splitting tensile and the flexural strengths increased. The compressive strength of the specimen tested was the highest and flexural strength the next and tensile strength lowest. The compressive, the tensile and flexural strengths of specimens made of fine sand were higher than those of coarse sand. The compressive, the tensile and the flexural strengths of specimens made of high pressure molding were higher than those of low pressure molding. In comparison with different additives, the specimens with carbon black was excellent and B.H.T. good and ferric oxide poor for thermal resistance. In relationship between the flexural strength with varying temperature from -23 deg C to 80 deg C, the flexural strengths decreased as temperature increased at 25%, 30% and 35% of binder contents, respectively. Especially at 60 deg C, the flexural strength significantly decreased. The decrement of flexural strengths and the weight losses after 7 days immersion in acid or alkali solutions were not significant. Fire resistance of the reclaimed plastic concrete was not significantly influenced by the contents of sand. However, the fire resistance of the reclaimed plastic concrete depended upon melting and ignition properties of the binder itself. Therefore a proper selection of the binder and the fire retardant are recommended in order to improve fire resistance of the reclaimed plastic concrete