An investigation on using solid waste materials as aggregate substitute in cementitious concrete composites.

摘要

The purpose of this investigation was to evaluate the possibility of using different granulated solid waste materials (plastics, fiberglass, and glass) as partial aggregate substitutes to the fine aggregate in a portland cement concrete mixture to produce new concrete composites. Three different types of concrete composites containing one of these aggregates were prepared. Four different volume percentages (5, 10, 15, and 20%) were utilized for each aggregate substitute. A control cementitious concrete composite was al so prepared as a reference for the new concrete composites. Three different test methods were conducted on these composites: compression, splitting tensile, and flexure tests. Standard ASTM procedures were followed in casting of and testing all the flexural beams and concrete cylinders and the curing of 28-day concrete samples.; Statistical procedures of the data obtained were used to determine any significant differences among the mechanical properties values of the tested concrete composites. These data were also represented graphically and analyzed to compare the new concrete composites with the control specimens. Furthermore, a scanning electron microscope was used to study the relationship between these mechanical properties and the microstructure and interfacial features of the new concrete composites. Optical photographs were also obtained to show the general fracture behaviors of these composites.; The main findings of this investigation revealed that increasing either the volume percentage of plastics or fiberglass aggregate substitute to the concrete composite led, in general, to a reduction of the compressive, splitting tensile, and flexural strengths. On the other hand, the stiffness of these concrete composites was either the same as or higher than (in case of plastics- and fiberglass-containing composites respectively) that of the control one. In case of glass-containing concrete composites, the average values of compressive and splitting tensile strengths of these composites were comparable to those of the control one. However, the values of the modulus of rupture and elasticity of all the glass-containing composites were the same as (and in some cases higher than) those of the control one. The present research study revealed also that the visual analysis technique could be useful to compare the properties of different types of concrete composites qualitatively.