Effects of Aggregate Micro Fines (AMF), Aluminum Sulfate and Polypropylene Fiber (PPF) on Properties of Machine-Made Sand Concrete

Hang He,Junjie Wang,Yuli Wang

doi:10.3390/app9112250

Abstract

With the depletion and increasing demand of river sand, machine-made sand could be used more and more in concrete. In order to improve the properties of machine-made sand concrete, the effects of the aggregate micro fines (AMF) content, aluminum sulfate, and polypropylene fibers (PPF) on the slump, compressive strength, water permeability, and the chloride permeability coefficients were investigated through a single factor test method, and related mechanisms were analyzed. The results show that the optimum contents of AMF, aluminum sulfate, and the polypropylene fiber are 10 wt%, 1 wt%, and 0.6 kg/m3, respectively. The optimum content of AMF improved the compactness of concrete. The addition of aluminum sulfate promoted the initial formation of ettringite, and thereby improved the compressive strength and the permeability resistance. The polypropylene fiber can modify the pore structure distribution of concrete and reduce the porosity, thereby improving the impermeability of the concrete. The compressive strength of the machine-made sand concrete could be increased by more than 20%, and the water/chloride permeability coefficients could be decreased by more than 45%.

Highlights

With the rapid development of China, the massive projects in civil engineering require more and more river sand as normal fine aggregates based on the main trend in concrete design
Others [11,12,13,14] reported that there is an optimum content of aggregate micro fines (AMF) for the properties of made sand concrete (MSC), and the existence of AMF could contribute to a higher compressive strength
Shen et al [11] reported that the highest compressive strength of MSC was achieved when there was 7.5% AMF in the machine-made sand

Summary

Introduction

With the rapid development of China, the massive projects in civil engineering require more and more river sand as normal fine aggregates based on the main trend in concrete design. The depletion of river sand could happen in a number of places, especially places that are further away from any rivers. In this condition, the use of machine-made sand [1,2,3] could be an easy and feasible option. Machine-made sand has several advantages, such as the existence of aggregate micro fines (AMF). Others [11,12,13,14] reported that there is an optimum content of AMF for the properties of MSC, and the existence of AMF could contribute to a higher compressive strength. Shen et al [11] reported that the highest compressive strength of MSC was achieved when there was 7.5% AMF in the machine-made sand

Methods

Discussion

Conclusion