Frost Resistance of Desert Sand Concrete

Abstract

Demand for medium sand has increased greatly with increasing infrastructure construction items. The shortage of construction sand resources has become a serious problem in many districts. It not only increases the engineering cost, and the overexploitation of river sand and mountain as medium sand also brings a series of serious environment problems. There are abundant desert sand (DS) resources in western China. If DS resources can be used to substitute medium sand to produce desert sand concrete (DSC), which was suitable for engineering practice, the environment can be improved and engineering cost can be reduced. Although many researchers had focused on the mechanical performance of DSC, there were few documents on the frost resistance of DSC. Frost resistance experiments of DSC with 50% desert sand replacement ratio (DSRR) and ordinary concrete (OC) were performed in this paper. Influence of freeze-thaw cycles on the mechanical properties of OC and DSC was analyzed. Experimental results showed that, with increasing freeze-thaw cycles, the damage, peak strain, and porosity increased, while elastic modulus, Poisson's ratio, and peak stress declined, the stress-strain curves tended to be flat. Under the same condition of freeze-thaw cycles, the frost resistance of DSC with 50% DSRR was higher than that of OC. Constitutive model of DSC after different freeze-thaw cycles was formulated. The results predicted by constitutive model agreed well with experimental results, which can provide technical support for DSC engineering practice.

Effect of Desert Sand on the Mechanical Properties of Desert Sand Concrete (DSC) after Elevated Temperature

“…When DSRR was less than 40%, with the increment of DSRR, desert sand can effectively fill the gaps between cement mortar and coarse aggregate. DSC became more compacted, which can increase the DSC strength [9,11,39]. When DSRR was 40%, the aggregate gradation curve was optimal, so that DSC relative compressive strength can arrive at the maximum value.…”

“…When DSRR was more than 40%, the specific surface area of fine aggregate increased. More grouts were needed to attach around fine aggregate, which caused the decrease in compressive strength [7,11,12]. Moreover, desert sand was formed by the weathering of loose rock, and the strength was lower than that of ordinary medium sand [11,[13][14][15][16].…”

“…Luo [9] analyzed the effects of sand ratio on DSC compressive strength, elastic modulus, tensile strength, and slump. Liu [10][11][12][13] carried out experiment to research the DSC mechanical properties. Zhang [14,15] studied the uniaxial properties of desert sand mortar after elevated temperature.…”

Effects of Desert Sand Substitution on Concrete Properties Using Desert Sand-Doped Quartz Sand as the Fine Aggregate

“…Most research about desert sand applications in concrete technology took the desert sand substitution ratio as being univariate, while the sand ratio and other indices of the mix proportion were controlled to be constant. Consequently, the workability and moulding quality of concrete were negatively affected as the substitution ratio increased, making concrete infeasible for engineering applications [15][16][17][18]. In this study, the concrete properties using desert sand-doped artificial sand were investigated with the premise that the mix proportions were adjusted to acquire the expected strength grades and fluidities, which are two of the most important indices in engineering activities.…”