Experimental Study On Basic Mechanical Properties And Durability Of HPP Fiber Polymer Modified Concrete

HPP fiber(plastic steel fiber)reinforced concrete has better bending and tension resistance,cracking resistance,impact resistance,corrosion resistance and fatigue resistance than ordinary concrete.Polymer modified concrete has better deformation ability,permeability resistance,durability,wear resistance and skid resistance than ordinary concrete.In this paper,the composite material design idea is used to compound polymer modified concrete and HPP fiber reinforced concrete to prepare HPP fiber polymer modified concrete with the above two kinds of excellent performance of concrete,so as to greatly improve the durability of concrete composite material.It is suitable for paving layer and building structure of road and bridge surface in northwest area and coastal area under complex corrosion condition.In order to provide some reference value for the future engineering application,this paper studies the performance of HPP fiber polymer modified concrete in many aspects under different HPP fiber content and length by referring to the existing concrete and fiber concrete specifications,and compares it with benchmark concrete and polymer modified concrete.The specific work contents and conclusions are as follows:(1)Carry out orthogonal test to determine the optimal polymer dosage.On the basis of the preliminary determination of the mix ratio of benchmark concrete,the orthogonal test is carried out to determine the optimal polymer content and finally determine the mix ratio of HPP fiber polymer modified concrete: Cement 411 kg,water 157 kg,sand 660 kg,stone 1124 kg,polymer 41.1kg,defoamer 4.11 kg,curing agent 10.3kg,HPP fiber 2.76 kg ～ 5.52 kg.(2)Carry out basic mechanical properties test to study the change rule of basic mechanical properties.Compared with the polymer modified concrete,the mechanical properties of HPP fiber polymer modified concrete,such as cubic compressive strength,axial compressive strength and static compressive elastic modulus,are improved,and in the range of 0 ～ 0.6%,the overall trend is first increased and then decreased.The enhancement effect of HPP fiber polymer modified concrete with HPP fiber content of 0.45% increased by 16.45%,22.16% and 23.43%,respectively.The splitting tensile strength and flexural strength of HPP fiber are improved much more than the compressive strength,and the splitting tensile strength and flexural strength are positively correlated with the HPP fiber content,which are increased by 31.78% and 28.26% respectively.(3)Carry out durability tests to study the enhancement effect of durability.Durability of HPP fiber polymer modified concrete was evaluated by freezing resistance,sodium sulfate erosion resistance and chloride ion penetration resistance.The freezing resistance,sodium sulfate erosion resistance and chloride ion penetration resistance of HPP fiber polymer modified concrete are positively correlated with the content of HPP fiber.Data software was used to process the test data,and a theoretical model was established to describe and predict the deterioration of HPP fiber polymer modified concrete in three different durability tests at any dosage from 0.3% to 0.6%.