Effect of crystalline admixture, fly ash, and PVA fiber on self-healing capacity of concrete

Understanding the Impacts of Healing Agents on the Properties of Fresh and Hardened Self-Healing Concrete: A Review

“…The CaCO 3 precipitation, as the self-healing product, in the presence of CA is coherent with the observations of Sisomphon et al [2], Roig-Flores et al [57,58], and Escoffres et al [59]. In addition, the use of CA is also beneficial for the recovery of mechanical properties that could achieve more than 78% strength regain [66]. Consequently, CA acts as a stimulator of the autogenous healing mechanism of concrete [45] and simultaneously may promote a durable concrete.…”

“…The phenomenon of strength enhancement might be explained by three reasons: (1) the filling effect of CA [57,58], (2) the role of CA as cement hydration activator by promoting the further densification of the microstructure [60] and (3) the production of CaCO 3 by CA inside the concrete matrix upon presence of moisture [66]. Microstructural analysis based on XRD and SEM revealed the presence of CaCO 3 , Ca(OH) 2 , C-S-H, crystalline Mg-phase and ettringite in CA concrete specimens [63].…”

Studies on Compressive Strength Microstructural Analysis of Self-Compacting Mortar with Bacteria

“…The authors look at the effects on the fresh and hardened properties of Self-Compacting Geopolymer Concrete (SCGC) mixtures due to Bacillus Licheniformis. Moreover, Mohd Nasim et al [21] have investigated the effect of crystalline admixture (CA), fly ash (FA) and PVA fibre on the ability of early-age cracks in concrete to self-heal. M1 is the control mix, M2 is the 0.1 percent Polyvinyl Acetate (PVA) fibre by volume mix, M3 is the 20 % partial cement replacement with fly ash mix and M4 is the 2 % CA by cement mass mix; these are the four mixes used.…”

An overview of a twofold effect of crystalline admixtures in cement-based materials: from permeability-reducers to self-healing stimulators

“…In general, the findings also showed that the presence of CA ensured better recovery with lower dispersion of results than the reference in water immersion and open-air exposure conditions. Nasim et al [27] found that the inclusion of CA increased the compressive and electrical resistivity recoveries in Moderate Strength Concrete (MSC), with a water/cement ratio of 0.4, at 42 days (see Tables 1 and 2 for detailed explanation). In contrast, Jiang et al [40] observed a modest increase in the compressive recovery and a considerable stiffness gain in the mixtures with 16% CA carbonate-based compared to the reference and other types of mineral admixtures, such as CSA and metakaolin.…”