Strength Time–Varying and Freeze–Thaw Durability of Sustainable Pervious Concrete Pavement Material Containing Waste Fly Ash

Abstract

Pervious concretes, as sustainable pavement materials, have great advantages in addressing a number of environmental issues. Fly ash, as the industrial by-product waste, is the most commonly used as cement substitute in concrete. The objective of this paper is to study the effects of waste fly ash on properties of pervious concrete. Fly ash was used to replace cement with equivalent volume method at different levels (3%, 6%, 9%, and 12%). The control pervious concrete and fly ash modified pervious concrete were prepared in the laboratory. The porosity, permeability, compressive strength, flexural strength, and freeze–thaw resistance of all mixtures were tested. The results indicated that the addition of fly ash decreased the early-age (28 d) compressive strength and flexural strength, but the long-term (150 d) compressive strength and flexural strength of fly ash modified pervious concrete were higher than that of the early-age. The adverse effect of fly ash on freeze–thaw resistance of pervious concrete was observed when the fly ash was added. The porosity and permeability of all pervious concrete mixtures changed little with the content of fly ash due to the use of equal volume replacement method. Although fly ash is not positive to the properties of pervious concrete, it is still feasible to apply fly ash as a substitute for cement in pervious concrete.

Durability Evaluation of Concrete with Multiadmixtures under Salt Freeze‐Thaw Cycles Based on Surface Resistivity

“…With the increase of FA content, the relative dynamic modulus of concrete decreases more greatly. erefore, with the increase of FA content, the salt freeze-thaw resistance of concrete decreases, as reported by Liu et al [35].…”

“…e mechanical properties of concrete with FA decrease with the increase of FA content, and the decrease range increases with the increase of FA content, which indicates that the secondary hydration degree of FA is low in the 28day strength formation process, which is not enough to improve the strength of concrete [35]. e surface resistivity FA plays the role of microaggregate filling, which can fill the internal defects of concrete [49].…”

“…Yuan et al used CT to obtain the bubble structure distribution information and proposed the void-to-void distance as a factor to evaluate the freezingthawing resistance with deicing salt performance of cement concrete [33]. Some environment-friendly mineral admixtures for concrete such as fly ash (FA), blast furnace slag (BFS), and silica fume (SF) are strongly recommended to improve salt freeze-thaw resistance because of their contributions to microstructure of concrete [34,35]. Studies on mechanism for salt freeze-thaw have suggested that the invasion of chlorides is responsible for damages from salt crystals, high degree of saturation, and additional hydraulic pressure [36,37].…”

Investigation on Durability Behaviour and Optimization of Concrete with Triple‐Admixtures Subjected to Freeze‐Thaw Cycles in Salt Solution

“…On the other hand, environment-friendly mineral admixtures for concrete such as fly ash (FA), blast furnace slag (BFS), and silica fume (SF) are strongly recommended to improve salt freeze-thaw resistance because of their contributions to microstructure of concrete [34,35]. Studies on mechanism for salt freeze-thaw have suggested that the invasion of chlorides is responsible for damage from salt crystals, high degree of saturation, and additional hydraulic pressure [36,37].…”

Application of Fuzzy and Rough Sets to Environmental Zonation for Concrete Durability: A Case Study of Shaanxi Province, China

“…Due to the various environmental conditions of concrete structures, the mechanism of durability deterioration is complex. For instance, carbonization [2], freeze-thaw damage [3][4][5], acid rain [6,7], and ion erosion [8][9][10][11][12] can directly affect the durability of concrete structures. It is necessary to take into account the in-service environmental condition when it comes to the design of new concrete structures and the evaluation and maintenance of existing concrete structures.…”