Bending resistance of PVA fiber reinforced cementitious composites containing nano-SiO2

Abstract

In this study, the effects of polyvinyl alcohol (PVA) fiber content and nano-SiO2 (NS) on bending resistance of cementitious composites were investigated including bending strength and toughness. PVA fiber contents from 0.6% to 1.5% were added in the composites. The NS contents was 0% and 2% by mass. The water to binder ratio (w/b) was 0.38 for all composites. The specimens were cured for 28 days under 20∘C and relative humidity of 95% before bending test. The results show that the bending strength was improved with PVA fiber content increasing and the maximum bending strength was obtained at PVA fiber content of 1.5%. Although PVA fiber increased bending resistance regardless of NS addition, the optimal content was 1.2%. When the fiber content was less than 1.2%, the bending resistance of cementitious composites increased with fiber content. However, the toughness began to decrease as PVA fiber content increased from 1.2 % to 1.5%.2% NS addition decreased both bending strength and toughness due to the fact that NS was prone to self-desiccation and flock together, resulting in micro crack and strength loss.

Comparison of Fly Ash, Pva Fiber, Mgo and Shrinkage-Reducing Admixture on the Frost Resistance of Face Slab Concrete via Pore Structural and Fractal Analysis

“…However, as shown in Fig. 3, the 90-day compressive strength of C3 concrete is about 6.1 % higher than that of C0 concrete, which is due to a superposition of the beneficial effects of fly ash and PVA fiber, i.e., the pozzolanic effects of fly ash at late age 10 and the strength enhancement effect of PVA fiber 57 .…”

“…First, the fibers have a fracture strength as high as 1500 MPa, which tends to increase the stress bearing capacity of concrete before cracking 55 . Secondly, the fibers can absorb the energy under tensile stress, reduce the stress concentration and improve the resistance to cracking 56,57 .…”

Effect of Surface Shape and Content of Steel Fiber on Mechanical Properties of Concrete

“…e specimens with 2% of twisted steel fiber exhibit a tensile strength which is approximately 32% higher than those with 2% of short straight steel fiber. Previous research has showed that corrugated and hooked fiber significantly improved the bond properties by three to seven times when compared to those with straight fiber [24,25]. It can be concluded that even if the content of steel fiber is the same, the different shape steel fiber has different effect on concrete mechanical property.…”

Laboratory experiment on the nano-TiO2photocatalytic degradation effect of road surface oil pollution

“…Berry and Mueller [15] used TiO 2 powder as the photocatalytic material and adhered it to wood chips with epoxy resin, and the test result showed that it could effectively degrade petroleum pollutants on the water surface. Zhang et al [16] also evaluated nano-TiO 2 in water treatment. King et al [17] and Yang et al [18] found that the photocatalytic technology was useful in the degradation of the oil in the Deepwater Horizon spill accident.…”