Effects Of Glass Fiber And Silica Fume On The Mechanics And Shrinkage Properties Of Cement Mortar

With the acceleration of urbanization,people pay more and more attention to new building materials.Among them,glass fiber as a cement-reinforced material has attracted the attention of many experts,and has become a research hotspot and future direction in the field of concrete.This material has excellent mechanical properties,high tensile strength,and large elastic modulus,which can effectively make up for the weakness of mortar and concrete,and improve its compression and bending resistance.In addition,glass fiber also has a good inhibition effect on the internal shrinkage of mortar and concrete.In engineering,it is shown to reduce shrinkage and cracking,which can solve the problems encountered in engineering.In this paper,the effects of different amounts(0,2.5%,5%,and 7.5%)of glass fiber chopped strands on the mechanical properties and shrinkage characteristics of cement mortar are studied first.The results show that glass fiber can effectively improve the compressive strength and flexural strength of cement mortar,and can also inhibit the self-shrinkage and dry shrinkage of mortar.Among them,the 28-day compressive strength of cement mortar with 5%glass fiber content increased by 23.66%to 60.37MPa compared with the reference group,and the self-shrinkage and dry shrinkage decreased by 16.5%and 14.12%,respectively.Secondly,the effects of different amounts(0,5%,10%and 15%)of glass fiber powder on the mechanical properties and shrinkage properties of cement mortar were studied.The results show that the amount of glass fiber powder has little effect on the flexural strength and compressive strength of the mortar,but it can effectively reduce the self-shrinkage and dry shrinkage of the mortar.Among them,the self-shrinkage and drying strain of 5%cement mortar were-411με and-763με respectively.Compared with the reference group,the self-shrinkage decreased by 40.09%and the dry shrinkage by 40.16%.5%glass fiber powder mixed with cement mortar has the largest reduction ratio and the best toughness.Finally,the mechanical properties and shrinkage properties of glass fiber cement mortar modified with 0,5%,10%and 15%silica fume are used.The results show that with the increase of the silica fume content,the flexural strength of the mortar becomes larger,the compressive strength increases first and then decreases,the folding ratio becomes larger,and the toughness increases.The compressive strength of glass fiber cement mortar with 10%silica fume content is the largest,reaching 66.82MPa,which is an increase of 10.6%compared with the reference group;Silica fume increases the shrinkage of glass fiber cement mortar,and both self-shrinkage and dry shrinkage become larger to varying degrees.The research in this paper shows that glass fiber is an ideal cement mortar reinforced material,which has obvious improvement in flexural strength.It can also increase the compressive strength within a certain dosage range,at the same time,it can inhibit the self-shrinkage and drying shrinkage of the mortar and increase the compression of the specimen To improve its toughness;silica fume can simultaneously increase the flexural strength and compressive strength of glass fiber mortar within a certain dosage range,but it will increase the self-shrinkage strain and drying shrinkage strain.Therefore,the effective use of glass fiber materials and silica fume resources has great prospects in the field of preparing high-performance concrete,and is of great significance for promoting the development of glass fiber concrete.Figure 26 table 12 reference 81...