Effect of Silica Fume and Polyvinyl Alcohol Fiber on Mechanical Properties and Frost Resistance of Concrete

To improve the mechanical properties and frost resistance of concrete, silica fume, and polyvinyl alcohol fiber compounded in concrete. The mechanical and frost resistance of concrete were comprehensively analyzed and evaluated for strength change, mass loss, and relative dynamic elastic modulus change by compressive strength test, flexural strength test, and rapid freeze-thaw test. The results showed that with the incorporation of silica fume and polyvinyl alcohol fiber, the compressive and flexural strengths of concrete were improved, and the decrease in mass loss rate and relative dynamic elastic modulus of concrete after freeze-thaw cycles were significantly reduced, which indicated that the compounding of silica fume and polyvinyl alcohol fiber improved the frost resistance of concrete. When the content of silica fume was 10% and the volume content of polyvinyl alcohol fiber was 1%, the comprehensive mechanical performance and frost resistance of concrete is the best. The compressive strength increased by 26.6% and flexural strength increased by 29.17% compared to ordinary concrete. Based on the test data, to study the macroscopic damage evolution of concrete compound silica fume and polyvinyl alcohol fiber under repeated freeze-thaw conditions. The Weibull distribution probability model and GM (1, 1) model were established. The average relative errors between the predicted and actual data of the two models are small and very close. It is shown that both models can reflect well the development of concrete damage under a freeze-thaw environment. This provides an important reference value and theoretical basis for the durability evaluation and life prediction of compound silica fume and polyvinyl alcohol fiber concrete in cold regions.

A study based upon the effect of polyvinyl alcohol fiber, iron slag and fly ash over the strength aspects of geo-polymer concrete

In this research work fly ash, iron slag and polyvinyl alcohol fiber was utilized to enhance the strength parameters of the concrete. Fly ash and iron slag were used as replacement of the cement and polyvinyl alcohol fiber was used as an additive at 0 %, 2 %, 3 % and 4 %. After this several samples were casted and then verified for numerous test. Compressive strength test was executed and it finds out that concrete containing Polyvinyl Alcohol fibers (with different curing methods) was showing increasing strength as compared to concrete deprived of Fiber. Specimens of oven cured samples shown a large increase in strength as compared to room temperature curing as shown in the result section. Compressive strength increases up to three percent of adding Polyvinyl Alcohol fiber after that strength decreasing. Flexure strength was carried on the Geo-Polymer concrete with different curing techniques and result show’s an impressive increase in flexural strength, but room temperature cured specimens show lesser growth as compared oven cured specimens. But not lower than concrete which didn’t have Polyvinyl Alcohol fiber in it. Flexural strength increases up to three percent of adding Polyvinyl Alcohol fiber in both the curing techniques and decreases at four percent as shown in the result section. Split tensile test was also carried out for both the curing techniques oven curing and room temperature curing. The samples which were cured in oven curing show impressive growth in strength. Maximum split tensile strength attained at three percent of adding Polyvinyl Alcohol fiber. With the help of UPV, it was found that the concrete that makes with the help of a Polyvinyl Alcohol Fiber is of good quality as shown in results.

Strength assessment of concrete using rice husk ash, recycled concrete aggregate and polyvinyl alcohol fiber

: This research work present the finest proper mix by adding and replacing with some other admixture materials having same properties as standard concrete materials. The substances that are used in this Rice husk ash (RHA) Recycled concrete aggregates (RCA) and polyvinyl alcohol fiber (PVA). Coarse aggregates was replaced with RCA at 50% and 0-20% RHA in scheming concrete mixes. For this, 5 to 20% (such as 5%, 10%, 15% and 20%) of RHA has been used as a fractional replacement of cement. PVA fiber has been added to this mix at fixed percentage of 0.50% by weight of concrete. 6 mm geometric length of PVA fiber which were aspect with ratio of 428 were used in this research work. In the present research work I did non-destructive and destructive tests after 7 days and 28 days. The values of tests were 10% for RHA and 50% of RCA with fiber fulfills which was PVA which were designed as for the requirement of construction industry. The results show that by adding more amount of RHA and RCA the concrete strength starts decreasing. Tests performed over concrete: Rebound Hammer Test, Flexural Strength Test, Water Absorption Test, Compressive Strength Test, Split Tensile Strength Test, and Ultrasonic Pulse Velocity Test.

Study on Mechanical Properties and Pore Structure of Hybrid Fiber Reinforced Rubber Concrete

In this work, to reduce the probability of brittle failure in the support structure of deeply buried high-stress soft rock roadways, hybrid-fiber reinforced rubber concrete (HFRRC) was investigated using the orthogonal test, and the effects of various factors on the performance were studied. The mechanical properties, pore structure, and microstructure of rubber concrete reinforced by basalt fiber (BF) and polyvinyl alcohol fiber (PF) were studied from macroscale, mesoscale, and microscale perspectives. The results revealed that the content of the rubber particles has a significant impact on strength. Further, the addition of the hybrid fibers to the concrete was found to have a positive effect on the splitting tensile strength and the flexural strength. However, no significant effect was observed on the compressive strength. Furthermore, it was found that the content of BF and PF have a significant impact on the energy dissipation capacity and ductility, and the influence of the PF content is greater than that of the BF content. The concrete with 10% rubber particles of 1–3 mm, a volume fraction 0.3% basalt fiber, and a volume fraction 0.2% polyvinyl alcohol fiber was obtained as the optimal mix proportions. Moreover, it was found that the random distribution of the rubber particles and the hybrid fibers optimized the pore structure, inhibited the expansion of the cracks, and reduced the brittleness of the concrete. The findings of this study can provide a useful reference for the application of an environmentally friendly material with recycled rubber aggregate and hybrid fiber.