改性组分对水泥基材料韧性的影响

Effects of modified compositions on toughness of cementitious materials

为掌握静力荷载和冲击荷载作用下水泥基材料的韧性及其主要影响规律,通过试验研究手段,采用折压比、冲击功等指标,分别研究了矿物掺合料、聚丙烯纤维、纤维素纤维、钢纤维以及橡胶颗粒对水泥砂浆在静力荷载作用下的折压比和冲击荷载作用下冲击破坏功的影响,并分析了不同组成砂浆的折压比和冲击功之间的相关性.结果表明,不同改性组分对砂浆折压比和冲击破坏功2参数存在不同的影响机理;当所掺改性组分的类型相同时,砂浆的冲击功随折压比增加而增大.为提高砂浆的折压比和冲击功,宜掺加变形能力好、抗拉强度较高且其与砂浆基体之间具有较大的粘结作用的改性组分.纤维与橡胶颗粒的复合掺入可较好地发挥叠加效应,进一步增强水泥基材料的冲击韧性.

Aimed at understanding the toughness characteristics of cementitious materials under static and dynamic load conditions,the parameters of flexural to compressive strength ratio and impact energy are used to analyze the effect of modified compositions such as mineral admixtures,polypropylene fiber,cellulose fiber,steel fiber and rubber particles on mechanical properties of mortar by flexural,compressive and impact load experiments.And also the relationships between flexural to compressive strength ratio and impact energy of mortar are discussed.Results indicate that different components have different effects on flexural to compressive strength ratio and impact energy under static and dynamic load,respectively.The impact energy of mortar with the same type compositions increases with the increasing flexural to compressive strength ratio.In order to improve flexural to compressive strength ratio and impact energy of mortar,not only good deformability but also excellent adhesive force on mortar matrix of modified compositions are needed.The compound of fibers and rubber particles can effectively improve impact energy of mortar owing to the synergistic effect.