Mechanical properties of preplaced lightweight aggregates concrete

et al. 2020

Materials

This study proposes a new cement mortar incorporating damping aggregate (DA) and investigates the mechanical properties and damping property of the cement mortar. Four types of DA were prepared, lightweight aggregate presaturated water and three types of polymer emulsion. Further, the effects of polypropylene fiber and rubber powder on the performance of the cement mortar were studied. The experimental results showed that the damping ratio of specimens containing 70% DA was approximately three times higher than that of the reference mortar, with a slight decrease in the mechanical properties. Adding fiber was more effective than rubber powder in improving the damping ratio of the cement mortar, and the optimal dosage of fiber was 0.5%.

Section: Introductionmentioning

confidence: 99%

Damping Property of Cement Mortar Incorporating Damping Aggregate

Tian

et al. 2020

Materials

“…Preplaced aggregate concrete (PAC), a novel low-cement-consumption concrete, is prepared by placing coarse aggregate into formworks and then injecting the grout mortar into the void between the coarse aggregate [1,2]. Based on the special preparation technology, compared with normal concrete (NC), development of PAC could achieve a number of benefits, typically in saving cement, solving the segregation of coarse aggregate, reducing energy consumption during the concrete mixing process, increasing concrete stiffness, reducing concrete shrinkage and so on [3][4][5][6][7][8][9]. In recent years, PAC has been used in concrete repair engineering, underwater construction, massive concrete structures, concrete track construction, nuclear power plant structures and so on [10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Development and Investigation of a New Low-Cement-Consumption Concrete—Preplaced Aggregate Concrete

2020

Sustainability

Reducing consumption of cement in concrete will achieve huge benefits in decline of carbon emission, conservation of natural resources and reduction of the cost of concrete. In this paper, the low-cement-consumption concrete, preplaced aggregate concrete (PAC), is prepared and 12 types of mixtures including four water–binder ratios (W/B) and three sand–binder ratios (S/B) are designed to detect the effect of W/B and S/B on the mechanical properties and failure mechanism of PAC. Experimental and analytic results indicate that the cubic compressive strength of PAC, splitting tensile strength of PAC and elastic modulus of PAC decrease with increase in W/B and S/B. At a similar compressive strength, more than 20% increment of elastic modulus of PAC is achieved when compared with normal concrete (NC); the descent stage of stress–strain curves of PAC are steeper than that of NC and the peak strains of PAC is lower than that of NC. Guo’s model with suitable values of parameters a and b can be used to describe the stress–strain relationship of PAC. Replacing NC by PAC in concrete structures will save 15–20% cement and achieve great environmental and economic benefits.

“…Aggregate accounts for approximately 60-70% of all raw materials in the concrete production [3][4][5][6]. However, concrete consumption is expected to increase with the continuous growth of the infrastructure industry [7,8]. Consequently, non-renewable aggregate resources may get exhausted [4].…”

Section: Introductionmentioning

confidence: 99%

Mechanical and Damping Properties of Recycled Aggregate Concrete Modified with Air-Entraining Agent and Polypropylene Fiber

Pei

et al. 2020

Materials

In this study, recycled aggregate concrete (RAC) modified with polypropylene fiber (PP) and air-entraining agent (AGA) was prepared, and the effects of PP and AGA on the static (compressive strength, Young’s modulus, and splitting tensile strength) and dynamic properties (dynamic modulus of elasticity and damping ratio) of RAC were investigated. The experimental results showed that the addition of an AGA and PP had a favorable effect on the damping ratio of the concrete, however, the addition of the AGA had a slightly negative effect on the mechanical performance of the concrete. The AGA and PP contents required to achieve the optimum damping ratio of the concrete with the least reduction in the mechanical performance were 0.02% and 0.10%, respectively. Furthermore, the addition of AGA was more effective than that of PP in improving the damping property of the concrete.