Experimental Study On Mechanical Properties And Durability Of Basalt Polypropylene Hybrid Fiber Reinforced Lightweight Aggregate Concrete

The study found that adding appropriate amount of fiber can improve the mechanical properties of lightweight aggregate concrete,preventing the expansion of cracks and change the failure mode.In this paper,two influencing factors,basalt fiber volume rate and polypropylene fiber volume rate,were selected for the test design.Basalt fiber volume rate is 0.05% 0.1% 0.15%,polypropylene fiber volume rate is 0.05% 0.1% 0.15%.16 sets of test pieces were designed according to different fiber volume ratios,including single basalt fiber and polypropylene fiber all the three groups,and 1 set of ordinary contrast specimen,which are to test about basic mechanical properties,resistance to water permeability,frost resistance,corrosion resistance to sulfates and so on.Basic mechanical test showed that basalt fiber can validly enhance lightweight aggregate concrete's compressive properties,when the basalt fiber volume rate was 0.15%,it's compressive strength will increase 24%,the best effect.The increase of tensile strength of lightweight aggregate concrete by polypropylene fiber is especially obvious.,when the volume ratio of single-doped polypropylene fiber is 0.05%,it is 26.9% higher than that of matrix.Among them,the single-fiber series is superior to the hybrid fiber series.In terms of failure mode,both polypropylene fiber and basalt fiber significantly reduce the number of cracks in the test block,and causing the matrix to exhibit plastic damage.Durability test showed that the hybrid fiber series of matrix on improving the performance of the durability of the whole series is better than that of single doped fiber.Basalt-polypropylene hybrid fibers can produce a "mixed effect" to improve the durability of lightweight aggregate concrete.Among them,in terms of impermeability,the better ratio volume fraction is 0.15% basalt fiber and 0.1% polypropylene fiber.In terms of freeze-thaw resistance,the basalt fiber volume fraction is 0.15%,and the polypropylene fiber volume fraction is 0.15% are the best combination..In terms of anti-sulfate corrosion,when the basalt fiber volume fraction is 0.05% and the polypropylene fiber volume fraction is 0.15%,the effect is optimal.In this paper,based on the results of the durability test of basalt-polypropylene hybrid fiber lightweight aggregate concrete,Fitting out the relationship among the strength loss of basalt-polypropylene hybrid fiber lightweight aggregate concrete 50 freeze-thaw cycles as well as the compressive strength of 14-day anti-sulfate corrosion resistance and its impermeability was obtained..On this basis,the specific function formula has been established through evaluating the durability of basalt-polypropylene fiber concrete from the perspective of impermeability.