Additional adsorbed water in recycled concrete

Abstract

Recycling the decasting concrete catches more attention in the world. It depends on the strength for construction bearing to utilize recycled concrete (RC). Mixture ratio is one key factor deciding strength, which is supported by a crucial parameter: water-cement ratio. So the calculation of unit water use in RC is the hot topic, it is crucial that additional adsorbed water should be determined. It is appropriate to adopt the form of full (or part) coarse aggregate adding natural sand. In the case of mixed coarse aggregate adding natural sand, the water in each stere of RAC should increase its percentage corresponding to the ordinary concrete in the mix proportion design, the calculating formula for the additional adsorbed water is put forward, by which the additional adsorbed water coincides better with the experimental data through verification, and which can provide a reference for the designer in RC mixed ratio.

Research on the Performance of Recycled-Straw Insulating Concrete and Optimization Design of Matching Ratio

“…The water consumption for this test included net water consumption and additional water consumption, the latter of which is composed of the additional water consumption of recycled coarse aggregate and straw. The water absorption of recycled coarse aggregate is approximately three times that of natural aggregate, so additional water was supplied to the recycled coarse aggregate to minimize the impact of its high water absorption on the effective water-cement ratio [46,47]. To maintain the desired workability of concrete, around 10-13 kg of additional water per cubic meter of concrete was added for every 1% increase in the straw admixture during the experiment [35].…”

“…the effective water-cement ratio [46,47]. To maintain the desired workability of concrete, around 10-13 kg of additional water per cubic meter of concrete was added for every 1% increase in the straw admixture during the experiment [35].…”

Measurement of Water Absorption of Recycled Aggregate

“…Therefore, the preparation procedures of natural aggregate concrete (NAC) are different to those of RAC. More specifically, the latter needs to consider the absorption of RA in the slurry, which is usually calculated by its saturated-surface-dried water absorption (W SSD ) [ 16 ]. Clearly, the accurate evaluation of the W SSD of RA is of great significance to control an effective water-to-binder (w/b) ratio (E w/b ) of RAC [ 17 ].…”

Un hormigón autocompactante eco-amigable con áridos gruesos reciclados

“…Tabsh and Abdelfatah (11) found that replacing natural coarse aggregates by recycled coarse aggregates (RCA) in concrete requires 10% of extra water in order to achieve the same slump. Owing to this particularity, the water withdrawal of unit volume of concrete with recycled aggregates should be increased on the basis of that of ordinary concrete (12).…”