Recent Advances on the Application of Layered Double Hydroxides in Concrete—A Review

Abstract

The issue of chloride induced corrosion of reinforced concrete is a serious problem affecting infrastructure globally and causing huge economic losses. As such this issue has gained a considerable attention in the scientific community in the recent past. Layered Double Hydroxides (LDHs) have recently emerged as a new class of concrete-additives with a potential to increase the chloride resistance of concrete and mitigate corrosion. LDHs are clay like structures consisting of positively charged layers of cations with associated hydroxides and exchangeable anions in between the layers. Due to this charge balanced structure, LDHs possess the property of encapsulating an anion from the environment and replacing it with an exchangeable anion present in its layers. Potential applications include chloride entrapment in concrete and delivery of corrosion inhibiting anions. However, many versatile compositions of LDHs can be easily synthesized and their application as cement additives reach far beyond corrosion mitigation in concrete. This review presents a summary of recent advances on the applications of LDH in concrete. An extensive set of recently published literature has been critically reviewed and trends have been identified.

Layered Double Hydroxide Catalysts Preparation, Characterization and Applications for Process Development: An Environmentally Green Approach

“…Owing to the above stated ion exchange property [144] with an option of discharging a tailored anion.…”

Review of the Application of Hydrotalcite as CO2 Sinks for Climate Change Mitigation

“…The ion exchange is the key feature that makes the use of LDH/CLDH in building materials attractive. These, together with the memory effect of CLDH, are the two suitable factors for the ion exchange and capture mechanism shown in Figure 10 In recent years, LDH/CLDH have emerged as a new class of engineering materials [75], which can aid in the corrosion control of concrete structures and potentially prolong their service life. Calcined hydrotalcite improves the durability of cement-base materials.…”

“…After calcination, a large number of active sites produced what in favour of the improvement effect of CLDH on cement [72]. Since hydrotalcites may be incorporated into various building material mixtures, mortars, concretes and backfills, their application as accessible and affordable materials is prospective [73][74][75]. However, research in the field of hydrotalcites and cementbased materials is still insufficient [72,76].…”

Hydrotalcites in Construction Materials

“…Yang et al used a 10% addition of a MgAl NO 2 layered double hydroxide, which led to the decrease of compressive strength by 14,2% and the flexural strength by 19,1% [110]. Xiong et al observed a 25% compressive strength decrease after the addition of 1-3% of MgAl layered double hydroxide [111]. The differences between the positive and negative influence on the compressive strength depend on the microstructure of both the hydrotalcites used and the concrete.…”

“…The differences between the positive and negative influence on the compressive strength depend on the microstructure of both the hydrotalcites used and the concrete. The usage of inappropriate hydrotalcites may cause the increase of porosity, which can also lead to faster ingress of chlorides or other undesired substances [111]. This porosity is also growing with the amount of hydrotalcites added to the concrete [112].…”