Experimental on Fracture Properties and Flexural Toughness of High Performance Concrete with Steel-PVA Hybrid Fiber
In order to study the strengthening and toughening effect of steel-PVA(polyvinyl alcohol)blended fibers on HPC(high performance concrete),16 sets of specimens were designed and fabricated by using steel fiber volume fraction,PVA fiber volume frac-tion and mineral powder dosing as triple factors,and four-point loading and three-point loading bending tests were conducted to obtain load(P)-mid-span deflection(δ)curves and load(P)-CMOD(crack mouth opening displacement)curves,the flexural toughness and fracture properties after 28 days of age were determined.The study shows that:the P-δ curve and P-CMOD curve become more full when the concrete is mixed with steel fiber or PVA fiber,which has a more obvious enhancement and toughening effect;especially when the 2 fibers and a certain amount of mineral powder are mixed into the concrete,the trend of the falling section of the curve be-comes more gentle,and the mixed fiber high performance concrete specimens have better deformation ability than the single fiber con-crete specimens,mixed with 1.5％of steel fiber,0.2％of PVA fiber and 20％of mineral powder has the best effect,the most signifi-cant improvement of bending toughness and fracture performance,with a good positive mixing effect.
steel-PVA hybrid fibersflexural toughnessfracture performancehybrid effectsorthogonal test
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