Flexural Performance of Alkali-Activated Slag Cements under Quasi-Static and Impact Loading

作者：Yardimci Mert Yucel^*; Aydin Serdar; Tuyan Murat

来源：Journal of Materials in Civil Engineering, 2017, 29(1): 04016192.

DOI：10.1061/(ASCE)MT.1943-5533.0001701

• Alkali-activated slag cement
• Mineral admixture
• Low-velocity impact
• Fracture energy

Effects of silicate modulus (Ms) of an activator solution and the matrix components of alkali-activated slag cement (AASC) on the flexural parameters of AASC mortars were investigated under static and low-velocity impact loadings. AASC mixtures in two different Ms (SiO2/Na2O) ratios were prepared by the partial replacement of ground granulated blast-furnace slag (GGBFS) with fly ash (FA), meta-kaolin (MK), and silica fume (SF). Impact load was generated by a free-fall of a hammer onto the simply supported notched beams from different heights. Test results showed that SF-incorporating AASC had similar impact resistance to the control AASC mixture at all tested velocities while the MK-incorporating AASC had significantly lower impact resistance with an Ms ratio of 0.8. The increase of Ms ratio had a profound effect only in the MK series. The dynamic increase factors (DIF) in AASC mixtures increased with impact velocity. Dynamic increase factors were found to be higher in the AASC mixtures having porous and fissured microstructures than the well-packed and compact ones. AASC mixtures having similar quasi-static flexural performance to a portland cement mortar presented higher low-velocity impact resistance, fracture energy, and ductility index values under impact conditions.