Study On Damage Actions Of Alkali-resistant Glass Fiber In Cement-based Materials

The high-speed development of China economy and Auto Industry stimulate highway transportation and highway constructing greatly, cement-based materials has been applied extensively in pavement materials. However, as brittle material with low flexural strength and high compressive strength, the cement-based materials can't meet the demand of pavement performances. Cement-based materials with alkali-resistant glass fiber of high flexural strength and elastic module is one of effective methods. But the alkali-resistant glass fiber in cement-based materials will be corroded, and the long-term strength will also decrease. Therefore, this paper makes an all-round study of alkali-resistant glass fiber's damage mechanism, analyzes and studies the long-term performance of alkali-resistant glass fiber cement-based materials.Firstly, the study takes the main research object on alkali-resistant glass fiber cement mortar, test the compressive strength and flexural strength with the same strength class cement mortar by standard curing and hot water-curing system, make a initial inquire into the damage mechanism of alkali-resistant glass fiber, and carriy on a contrast analysis of the damage of alkali-resistant glass fiber both in ordinary portland cement mortar and the cement mortar mixeh with silicate fume.Secondly, cement mortar was modified by addition of seed crystal in order to strengthen the damage environment of alkali-resistant glass fiber, study on the interaction of the chemical erosion and physical injury by different curing system, to summarize the damage mechanism of alkali-resistant glass fiber in cement-based materials.Finally, test chloride diffusivity coefficient and porosity of cement mortar in different curing conditions, and use SEM to explore the reason of cement-based materials losing long-term strength, alkali-resistant glass fiber damage mechanism and the effect of seed crystal/silica fume on alkali-resistant glass fiber.The study has great significance for improving the strength and durability of cement-based materials, and makes the application of alkali-resistant glass fiber in road material much more reliable.