橡胶改性及其对橡胶水泥基质材料性能的影响

本文基于提高橡胶-水泥基质材料的力学性质的目的,对橡胶进行磺化-脲化改性.采用水接触角、红外光谱、粘接强度、抗压抗冲击强度等微观宏观测试技术考查了橡胶改性对橡胶水泥基质材料性能的影响.结果表明:橡胶氧化-脲化改性后,在橡胶表面引入了大量羰基、酰胺基等极性亲水性基团,使橡胶表面的浸润类型由憎水性质变为了亲水性质,大大增加了橡胶与水泥基体的界面相互作用,使橡胶与水泥浆体的粘接强度提高了33.4%.橡胶改性对减缓橡胶水泥基质材料的抗压强度降低有确定的效果,但是这种效果在橡胶水泥混凝土中比在水泥砂浆中更突出.橡胶掺量为细集料的30%或以下时,氧化-脲化改性的橡胶混凝土的抗压强度能够达到30 MPa以上,可以满足中等强度混凝土的要求.

Rubber Modification and Its Influence on the Properties of Rubber Cement Matrix

Based on the purpose of improving the mechanical properties of rubber-cement matrix, the rubber was modified by oxidation and urea, and the micro-macroscopic test techniques such as water contact angle, infrared spectrum, adhesive strength, and compressive strength and impact strength were used to investigate the properties of the modified rubber cement matrix.The results show that after the rubber is oxidized and urea-modified, a large amount of hydrophilic groups such as carbonyl and amide groups are introduced on the surface of the rubber, which change the rubber surface from hydrophobic to hydrophilic.So the interface action between the rubber and cement matrix is greatly increased, and the bonding strength between rubber and cement paste is increased by 33.4%.The rubber modification has definite effect in reducing the rubber cement matrix material compressive strength reduction, but this effect is more prominent in the rubber concrete than in the rubber mortar.When the rubber content is 30% or less of fine aggregate, the compressive strength of the modified rubber concrete can reach above 30 MPa, which can meet the requirements of medium strength concrete.