摘要
通过在天然骨料中掺加部分再生骨料,配制了4组骨料(骨料组号依次为RA0,RA25,RA50和RA75,总骨料中再生骨料体积百分比依次为0%,25%,50%和75%)。首先对4组骨料的压碎指标和吸水率进行了测试,其次用4组骨料配制了4组混凝土,对混凝土进行了抗压强度和抗折强度试验。分析骨料测试数据和强度试验数据得出:天然骨料(RA0)压碎指标变异系数为0.095,吸水率变异系数为0.089,其他3组再生骨料压碎指标变异系数为0.185~0.211,吸水率变异系数为0.176~0.243,再生骨料压碎指标和吸水率的离散性相对于天然骨料明显增大,但其离散性与再生骨料掺量对应关系不明显。掺加部分再生骨料后,混凝土抗压强度和抗折强度随再生骨料体积百分比增加表现出先增大后降低,增大幅度大约为6%和5%,降低幅度大约为12%和16%,当天然骨料中再生骨料体积百分比为25%时强度最高。用天然骨料配制的混凝土,其抗压强度变异系数为0.072,抗折强度变异系数为0.106,用再生骨料配制的混凝土,其抗压强度变异系数为0.114~0.137,抗折强度变异系数为0.128~0.148,用再生骨料配制的混凝土相对于用天然骨料配制的混凝土,其抗压强度、抗折强度离散性较大,但其离散性与再生骨料掺量对应关系不明显。结果表明:在天然骨料中掺加部分再生骨料配制混凝土是可行的;掺加后对混凝土抗压强度和抗折强度有一定影响,且强度离散性相对较大。
Four groups of aggregates were prepared by adding partially recycled aggregates to natural aggregates(The aggregate numbers were RA0,RA25,RA50 and RA75,and the volume percentage of recycled aggregates in the total aggregate was in turn 0%,25%,50%and 75%).In this paper,the crushing index and water absorption of the four groups of aggregates were tested first.Then,four groups of concretes were prepared with four sets of aggregates,and the compressive strength and flexural strength tests were carried out on the concrete.According to the test data:for the natural aggregate(RA0),the coefficient of variation of crushing index is 0.095 and that of water absorption is 0.089.For the other three groups,the coefficient of variation of crushing index of is 0.185~0.211,and that of water absorption is 0.176~0.243.The dispersion of the crushing index and water absorption is significantly increased compared with the natural aggregate,but the relationship between the dispersion and the amount of recycled aggregate is not obvious.After adding a part of recycled aggregate,the compressive strength and flexural strength of the concrete increased first and then decreased with the increase of the volume percentage of the recycled aggregate in the total aggregate.The increasing rate was about 6%and 5%,and the decrease was about 12%and 16%,the highest strength appeared when the volume percentage of recycled aggregate in the total aggregate is 25%.For the concrete with natural aggregate,the coefficient of variation of the compressive strength and the flexural strength were 0.072 and 0.106 respectively.For the concrete with recycled aggregate,the coefficient of variation of the compressive strength and the flexural strength were 0.114~0.137 and 0.128~0.148.Compared with the concrete with natural aggregate configuration,the compressive strength and flexural strength of the concrete with recycled aggregate are more discrete,but the correlation between the dispersion and the amount of recycled aggregate is not clear.The results show that it is feasible to mix part recycled aggregate into natural aggregate to prepare concrete.Adding part recycled aggregate has certain influence on concrete compressive strength and flexural strength,with the strength dispersion relatively bigger.
作者
陈海霞
宋学庆
CHEN Haixia;SONG Xueqing(China Coal Xi’an Design Engineering Company Limited,Xi’an 700054,China;China Electronic Research Institute of Engineering Investigation and Design,Xi’an 700054,China)
出处
《西安科技大学学报》
CAS
北大核心
2021年第2期290-297,共8页
Journal of Xi’an University of Science and Technology
基金
国家自然科学基金项目(51379015)。
关键词
再生骨料
混凝土强度
离散性
压碎指标
吸水率
标准差
变异系数
recycled aggregate
concrete strength
dispersion
crushing index
water absorption
standard deviation
coefficient of variation
