PERFORMANCE COMPARISONS OF IMPROVED TRUCK MIXER AND FIXED MIXER

摘要

In this study, a closed recycling system of concrete in urban area by using truck mixing plant is proposed as one of advanced recycling system of concrete resources. Truck mixing plant consists of improved truck mixer and small-sized storage and measuring equipment of cement and aggregate, and this batching plant can be mobile. Thus, the site occupied by concrete mixing plant is narrower as compared to that of fixed mixing plant. It is thought that truck mixing plant is suitable to a closed recycling system of concrete in urban area because urban area hardly has large open space. In spite of the obvious need for comprehensive study of truck mixing, however, there is little study on truck mixing in our country. Then, first of all, performance comparisons of improved truck mixer and fixed mixer by using concrete made with normal aggregate were carried out. The fresh properties, strength development and durability of concrete were examined in this study. It is possible to make concrete that does not have great difference in performances about slump, compressive strength and Young's modulus as compared with concrete made by using fixed mixer, when concrete is mixed for at least 1.5 minutes by using improved truck mixer. Moreover, from the results of air content examination, it is concluded that the optimum mixing time of improved truck mixer was for 5 minutes in this study.