Title: Simulation Analysis of Pumping and Its Variability for Manufactured Sand Concrete

Author(s): Guoju Ke, Jiaqian Wang, and Bo Tian

Publication: Materials Journal

Volume: 116

Issue: 3

Appears on pages(s): 35-42

Keywords: air void structure; megabyte (MB) value; pumpability; pumping variability; stone dust (SD) content; superabsorbent polymer (SAP)

DOI: 10.14359/51714504

Date: 5/1/2019

Abstract:
To solve the problem of manufactured sand concrete in the pumping process being very prone to plugging, a pumping resistance tester is used to test the influences of stone dust (SD) content and megabyte (MB) value of the manufactured sand, fly ash, silica fume, superabsorbent polymer (SAP), and air-entraining agent on the pumpability of manufactured sand concrete with different intensities, including push distance and pumping resistance. Furthermore, variations in the performance of the manufactured sand concrete before and after pumping are analyzed, including slump, slump flow, density, push distance, pumping resistance, compressive strength, chloride ion anti-permeability, and air void structure. Results show that SAP has shown a significant reduction in pumping resistance, both in low-strength concrete and in high-strength concrete. In the process of pumping, the pumping pressure causes the air void structure of the hardened manufactured sand concrete to change. The number of big air voids decreases, air void ratio increases, total porosity is reduced, and the resistance to chloride ion permeability is superior to the level before pumping.