摘要
石灰石在开采和加工成机制山砂过程中产生了大量的废弃石灰石粉,石粉的堆放和去除会造成土地资源的浪费以及环境污染,为此,可将石粉加入砂浆中,以实现对石粉的合理应用.但是砂浆在加入石粉后会出现大量收缩,其耐久性大大降低.为了避免这种不利影响,将石粉等量取代水泥后的砂浆干燥收缩情况进行试验,研究了不同石粉含量和粒径对砂浆干燥收缩的影响.试验结果表明:在不同石粉粒径下,采用适量的石粉等量代替水泥可以有效减小混凝土的干燥收缩值,当石粉替代率大于15%时,砂浆干燥收缩值不断增大,石粉最佳替代率为 10%;在不同石粉含量下,石粉粒径为 800目和 1 250目下的砂浆干燥收缩值均较小,可作为工程实际中石粉外掺量的参考值.
Abstract
In the process of mining and processing limestone into machine-made sand,a large amount of waste limestone powder is produced.The stacking and removal of stone powder will cause waste of land resources and environmental pollution.The drying shrinkage of the mortar after replacing the cement with the same amount of stone powder was tested,and the effects of different stone powder contents and different stone powder particle sizes on the drying shrinkage of the mortar were studied.The test results show that the drying shrinkage value of concrete can be effectively reduced by using an appropriate amount of stone powder to replace cement when the stone powder replacement rate is greater than 15%,the dry shrinkage value of mortar increases continuously,and the best replacement rate of stone powder is 10%.Under different stone powder content,the drying shrinkage value of mortar with stone powder particle size of 800 mesh and 1 250 mesh is smaller,in engineering practice,the stone powder of these two particle sizes can be selected as the external dosage.
万方数据