降低高强混凝土脆性的试验研究

Research of Decreasing Brittleness of High Strength Concrete

摘要:

采用外掺掺合料磨细矿渣、硅粉和粉煤灰及聚丙烯纤维的方法来研究它们对降低高强混凝土脆性的作用，并分析了相应的作用机理．结果表明：单掺磨细矿渣时，当其掺量为25％，则高强混凝土的脆性最低；磨细矿渣、硅粉和粉煤灰各自复掺时，高强混凝土脆性较单掺25％磨细矿渣的进一步降低，且降低幅度大致相当；三掺磨细矿渣、硅粉和粉煤灰时，高强混凝土脆性的降低幅度更大．当聚丙烯纤维的掺量控制在0．24％以内时，高强混凝土的脆性随着聚丙烯纤维的掺加而降低；当聚丙烯纤维与硅粉复掺时，高强混凝土的脆性系数又进一步降低．

Abstract:

In this paper, brittleness of high strength concrete(HSC) was improved by adding mineral admixtures such as ground slag(GSL), silica fume(SF) and fly ash(FA) and polypropylene fiber(PF). Brittleness coefficient was taken in the test to describe brittleness of HSC. And mechanism is analysed. Testing result shows that when only ground slag is added, brittleness of HSC decreases when its content is 25%, when two of the three mineral admixtures are added into HSC, brittleness decreases a little more and it does not change very much no matter which two are mixed; brittleness is the lowest when the three mineral admixtures are added. When content of polypropylene fiber is lower than 0.24%, brittleness of HSC is improved with the increasing content of polypropylene fiber. And when mixed with silica fume, its brittleness reduces a little more.