粉煤灰取代不同集料对再生混凝土路面砖性能影响的试验研究  

Experimental study on the effect of replacing different aggregates by fly ash on the performance of recycled concrete paving brick

作　　者：邢智岩 阎蕊珍 张泽平 李航宇 XING Zhiyan;YAN Ruizhen;ZHANG Zeping;LI Hangyu(College of Architecture and Civil Engineering,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工工大学建筑与土木工程学院,山西太原030024

出　　处：《混凝土》2020年第8期156-160,共5页Concrete

摘　　要：力学性能是再生混凝土的重要性能之一,许多因素对再生混凝土的力学性能有着不同程度的影响。将废弃混凝土破碎、筛分作为骨料制成再生混凝土路面砖,并以不同比例(2%、4%、6%)粉煤灰取代再生混凝土中的水泥和细骨料,对比7组再生砖试块在14、28 d龄期下的孔隙率、抗压强度、抗折强度。试验结果表明,再生混凝土路面砖的孔隙率随粉煤灰取代率的增加而增加。不同龄期下,粉煤灰取代率在4%以内时,再生砖的抗压、抗折强度基本随着取代率的增加而增加,其中抗折强度增加显著;粉煤灰取代率为4%时,再生砖的抗压、抗折强度均达到较大值;当粉煤灰取代率超过4%时,强度有所降低,但仍高于水泥再生混凝土砖的强度。Mechanical properties are great importance properties of recycled aggregate concrete,and variously influenced by many factors.Recycled concrete paving bricks are prepared by using recycled concrete as aggregate,meanwhile,the cement and fine aggregate in recycled concrete is replaced by fly ash at replacement ratio of 2%,4%and 6%.The physical and mechanical properties of the brick samples at 14 d and 28 d age was respectively discussed for 7 types of recycled concrete,including porosity,compressive strength and flexural strength.The test results indicated that the increase of replacement ratio of fly ash led to the increase in porosity of recycled concrete brick.The compressive strength,especially flexural strength of recycled bricks increase with replacement ratio increase of fly ash at different ages,at the incorporation range less than 4%.The larger values for both of the mechanical properties of concrete bricks were obtained at 4%of replacement ratio of fly ash.The strength of the bricks was superior to that of concrete mixes despite the reduction in strength of the bricks with replacement ratio of fly ash over 4%.

关 键 词：再生混凝土 粉煤灰 抗压强度 抗折强度 孔隙率 

分 类 号：TU528.041[建筑科学—建筑技术科学]