Suitability of Blending Rice Husk Ash and Calcined Clay for the Production of Self-Compacting Concrete: A Review

Abstract

One principal approach to achieve self-compacting properties is the increased amount of finer constituents of the mixture. This, in turn, increases cement consumption leading to higher greenhouse gas emissions. Pozzolanic materials, like rice husk ash or calcined highly kaolinitic clays, have gained increased attention as supplementary cementitious materials in self-compacting concrete production. These materials could be viable alternative supplementary cementitious materials for sub-Saharan Africa which already lacks fly ash, slag and silica fume. This current effort reviews the impact of rice husk ash and calcined clays for the production of self-compacting concrete. Special focus is on their impact on rheological, mechanical and durability properties of self-compacting concrete. Rice husk ash and, in particular, calcined highly kaolinitic clays are introduced as technical and cost-effective supplementary materials for use in self-compacting. The review disclosed a lack of knowledge when it comes to the use of low-kaolinitic calcined clays as sole SCM or together with rice husk ash, which could be a very promising combination for e.g., several countries in Africa. Further studies are needed on the rheological properties, shrinkage, creep, and durability of self-compacting concrete produced with other calcined common clays and their blend with rice husk ash.

Keywords: calcined common clays; compressive strength; creep; durability; metakaolin; rheology; rice husk ash; self-compacting concrete; shrinkage.

Figure 1

Micromorphology of rice husk ash (RHA) showing (a) outer surface (b) inter layer (c) Inner surface (d) transmission electron microscopy (TEM) image of RHA [63].

Figure 2

Slump flow of self-compacting concrete (SCC): Kannan [30], Chopra et al. [31], Rahman et al. [106], Madandoust [34], Gill [61].

Figure 3

Viscosity of SCC: Chopra et al. [31], Kannan [30], Gill [61], and Madandoust [34].

Figure 4

Blocking ratio of SCC: Chopra et al. [31], Kannan [30], Gill [61], Madandoust [34].

Figure 5

Compressive strength of SCC: Chopra et al. [31], Kannan [30], Kavitha [53], Madandoust [34], Vivek [107], and Gill [61].

Figure 6

Ultrasonic pulse velocity of SCC [30].

Figure 7

Modulus of elasticity: Molaeiraisi [116], He [117], Ramezanianpour et al. [118], Barkat et al. [22], Johari [119].

Figure 8

Drying shrinkage and creep of concrete produced with RHA: He [117].

Figure 9

Plastic, autogenous and total shrinkage of concrete produced with metakaolin (MK) [120].

Figure 10

Shrinkage and creep of conventional vibrated concrete (CVC) produced with MK [120].

Figure 11

Water absorption of SCC produced with RHA and MK: Kannan [110], Rahman [106], Madandoust [34], Gill [135].

Figure 12

Porosity of SCC produced with RHA and MK: Chopra et al. [31], Barkat et al. [22], Gill [135].

Figure 13

Rapid chloride penetration of SCC produced with RHA and/or MK [110].

Figure 14

Compressive strength loss of SCC [135].

Figure 15

Relative compressive strength of SCC subjected to F-T [153].