Experimental Study on Modification of Low-grade and Machine-made Sands

Abstract

Abstract In order to better apply low-grade and machine-made sands, this paper adopts the control test to investigate the influence of low-grade and machine-made sands with different proportions on motor fluidity, setting time and compressive strength, and modification effects of different mud inhibitors on low-grade and machine-made sands, proceeds the study on suitability of different kinds of fine low-grade and machine-made sands, and conducts the scale-up experiment in the concrete. The research results show that the content of fine low-grade and machine-made sands can substantially influence the water-reducing effects of polycarboxylate superplasticizer, affect the motor fluidity, compressive strength and setting time. After comparing different kinds of mud inhibitors, it turns out that HEDP has better effects, and can improve the low-grade and machine-made sands to certain degree; after comparing the polyethylene glycol (PEG) with different molecular weights, it turns out that the less the molecular weight is, the better the mud resistance effects are; PAANa has the best effects, and can remarkably improve the motor fluidity, prolong the setting time, enhance the compressive strength, and has better adaptability to different kinds of low-grade and machine-made sands, same significant application effects in concrete.