废弃混凝土制备再生骨料及其性能研究

Study on the Preparation and Performance of Recycled Aggregate Made by Waste Concrete

着重进行了废弃混凝土生产再生粗骨料和再生细骨料的试验,测定了其相关基本性能,试验结果表明:再生骨料的基本性能与天然骨料相比存在着一定的差异,这是由于再生骨料的表面有包裹着约为30%左右的水泥砂浆,导致再生骨料的表面粗糙、棱角较多,使得再生骨料的空隙率大、坚固性差、压碎指标值较高,这些特点会影响再生骨料混凝土的强度和耐久性;但是再生骨料表面粗糙,针片状含量较小,吸水率大,这些特点会使再生骨料与新的水泥砂浆有良好的黏结性,对于再生混凝土的成型有一定的积极作用。

The test focuses on the research of the production of recycled coarse aggregate and the recycled fine aggregate based on the waste concrete. In addition, the article also tries to test the basic performance of the recycled aggregate. The test results show that the basic properties of recycled aggregate still have some differences comparing with natural aggregate. Due to the 30 % of cement mortar wrapping on the surface of recycled aggregate, the surface of recycled aggregate is rough and has sharp edges, which make the recycled aggregate have large void ratio, poor sturdiness and high crush index value. These characteristics will affect the strength and durability of recycled aggregate concrete; but other characteristics of recycled aggregate, such as rough surface, small content because of needle--like and large water absorption will make the recycled aggregate have good adhesion with new cement mortar, which has certain positive effect on the formation of recycled concrete.