The replacement of natural sand by 60% of lightweight sand, by volume, was found to reduce autogenous shrinkage from 530 to 35 µm/m at 91 d.
This paper presents an experimental study to evaluate effect of cumulative lightweight aggregate (LWA) content (including lightweight sand) in concrete [water/cement ratio (w/c) = 0.38] on its water absorption, water permeability, and resistance to chloride-ion penetration.
Test results indicate that the use of lightweight sand was shown to be more effective in mitigating shrinkage than enhancing compressive strength.
This included the use of various contents of CaO-based and MgO-based expansive agents, shrinkage-reducing admixture, and pre-saturated lightweight sand.
In some combination, the use of shrinkage mitigating admixtures was found to reduce the 91-d compressive strength ranging from 8to2020 MPa, even when 60% lightweight sand was employed.
The incorporation of 10% CaO-based expansive agent in UHPC with 60% lightweight sand subjected to 7 d of moist curing exhibited the best overall performance with 91-d autogenous shrinkage of 110 µm/m in expansion and 91-d total shrinkage (autogenous shrinkage after 1 d plus drying shrinkage) of 580 µm/m (also in expansion).
The coupled effect of using 60% lightweight sand and either CaO-based expansive agent, MgO-based expansive agent, or shrinkage-reducing admixture can reduce autogenous shrinkage at 91 d by up to 600 µm/m and drying shrinkage by up to 700 µm/m.
Similar results were obtained when a lightweight matrix containing sand was subjected to the same sea water environment.
This paper presents an experimental study using recycled crumb rubber and native silty sand to produce a lightweight, soil-based, rubberized controlled low strength material (CLSM) for a bridge approach repair.
This paper presents the testing of 12 continuous beams made of all-lightweight, sand-lightweight and normal weight concrete having maximum aggregate sizes of 4, 8, 13 and 19 mm.
