Experimental Study of Chloride Resistance of Polypropylene Fiber Reinforced Concrete with Fly Ash and Modeling

Abstract

Herein, the paper reports an experimental investigation lasting one year on the chloride resistance of polypropylene fiber (PF) reinforced concrete with fly ash (FA). Four influential factors at four levels were studied, viz. water to binder ratio (w/b) (0.53, 0.34, 0.29, and 0.25), PF dosage (0%, 0.06%, 0.08%, and 0.1% in volume basis of the total volume of concrete), FA content (0%, 15%, 25%, and 35% in mass substitution ratio of cement) and concentration of NaCl solution (0%, 3%, 5%, and 7%). Dry–wet cyclic immersion and long-term soaking were taken into consideration in addition to the aforementioned factors. A L16(44) orthogonal table was used to sequence influencing factors and to determine the optimal combination. Results showed that 7% NaCl solution caused the highest chloride content in 0–5 mm depth, whilst the w/b ratio of 0.25 curbed the chloride penetration within 10 mm even for concrete subjected to dry–wet cyclic immersion for 360 d. Subsequently, a respond surface model (RSM) basing on polynomials was constructed to visually evaluate the effect of PF dosage and FA content. Results clarified that a cubic model was more precise and PF dosage and FA content turned out to have the positive facilitation to chloride resistance. The positive effect of PF however is not consistent and commensurate for concrete with varied fly ash content. Finally, a fuzzy logic based nonlinear model accommodating all seven influencing factors was verified to be proper and adaptive in predicting chloride content.

Physical, mechanical, and durability properties of concrete containing different waste synthetic fibers for green environment – A critical review

“…However, further increase of the waste nylon fiber reduces the chloride ion penetration resistance in the concrete matrix compared to the control mixture. The same observation with Chen et al [ 117 ] found that increasing the replacement of synthetic fiber can downfall concrete chloride migration resistance. This is mainly due to the reason the higher replacement of waste synthetic fiber can cause the void occurrence in the concrete matrix that can allow the migration of chloride.…”

“…Especially, the study found employing waste synthetic fibers by 1 % to the weight of concrete is 10 % more resistant than conventional concrete. This is mainly due to waste synthetic fibers are impermeable materials and can permit good holding together of the concrete matrix that mitigates the entrance of chloride ions and resists the corrosion of steel bars in concrete structures [ 117 , 119 , 120 ].…”

The Durability of High-Volume Fly Ash-Based Cement Composites with Synthetic Fibers in a Corrosive Environment: A Long-Term Study

“…Incorporating supplementary cementitious materials (SCMs) in concrete to assess their influence on fresh and hardened properties and durability of concrete has been discussed and widely promoted [8][9][10][11][12][13][14][15][16][17]. The researchers have acknowledged using F-FA to enhance concrete's fresh and hardened properties [4,5,9,[18][19][20][21][22].…”

“…Concrete mixes containing varying amounts of F-FA with the highest replacement volume (35%) and PP fibers between 0-0.1%, investigated for chloride resistance, show reduced chloride ingress for a water-binder ratio of 0.25. Resistance to chloride increases with a higher fiber content and F-FA volume [16]. Studies on using hybrid fibers such as PP, coated basalt fibers, steel fibers, and their influence on engineered cement composites containing high-volume F-FA show that hybridization helps improve such composites' strength and durability [48,49].…”

Experimental Investigation and Modeling of the Sulfur Dioxide Abatement of Photocatalytic Mortar Containing Construction Wastes Pre-Treated by Nano TiO2

“…Apart from traditional pozzolanic materials such as fly ash and furnace slag, many researchers have tried to find new materials that are more adaptable to the local situation. For example, it was reported that marine clay can be utilized with high added value as a supplementary binding material in manufacturing sustainable concrete products [22,23]. Recycled fine aggregates and recycled glass powder can be co-used in concrete production, which reduces the total carbon dioxide emission by about 19% [24,25].…”