Effect of utilizing unground and ground normal and black rice husk ash on the mechanical and durability properties of high-strength concrete

Abstract

The aim of the present study is to investigate the effects of utilizing different processings of normal rice husk ash (RHA) and black rice husk ash (BRHA) on the mechanical and durability properties of highstrength concrete (HSC). Mechanical and durability properties of HSC were evaluated on concrete mixes containing unground BRHA and RHA and ground BRHA and RHA, their average particles sizes being 165, 85, 67 and 24 lm, respectively. The replacement of ordinary Portland cement with the ashes was adopted at 20%. The results showed that incorporating any form of RHA and BRHA in HSC reduced the slump value. The surface areas of RHA and BRHA, not their carbon content, determined the dosage of superplasticizer needed to achieve a targeted slump value. Concrete with unground and ground RHA incorporated exhibited 30% higher compressive strength while unground BRHA produced 30% lower compressive strength than that of the control concrete. Incorporating unground and ground RHA showed a synergy between filler and pozzolanic effect and had insignificant difference in mechanical and durability properties of the concretes. Meanwhile, incorporating ground BRHA showed a dominant filler effect in the concrete. Overall, the improvement of splitting tensile strength and modulus of elasticity of both RHA and GBRHA concrete showed a similar trend to that of the compressive strength of RHA concrete. The durability of concretes with unground and ground RHA and ground BRHA incorporated showed better performance than that of the control concrete. The material with 20% ground BRHA as partial cement replacement in HSC of Grade 50 could be used without any reduction in the mechanical and durability properties. Use of unground BRHA is not recommended because it did not improve these properties.

Effect Of Quarry Dust On Mechanical Properties Of Rice Husk Ash-Based Concrete For Sustainable Environment

“…The rice husk ash has a significantly elevated specific surface area, hence facilitating prompt water absorption upon its incorporation. [3], [18]. As a result, it can be seen that for various mixes, the slump values are lower than reference mix M0 by roughly 9.33%, 13.7%, 17.8%, 21.9%, 26.0%, and 31.5%, respectively.…”

“…The potential explanation for this drop might be attributed to the enhanced water absorption capability of quarry dust and rice husk ash. Nevertheless, to get comparable workability to that of fresh control concrete, a specific dose of superplasticizer is required for RHA concrete [18]. The rice husk ash has a significantly elevated specific surface area, hence facilitating prompt water absorption upon its incorporation.…”

Factors affecting the CO2 emissions, cost efficiency and eco-strength efficiency of concrete containing rice husk ash: A database study

“…Bolla et al (2015) stated that the RHA significantly improved the concrete durability in particular the resistance of concrete to sulphate attack. Bahri et al (2018) also used black and grey RHA as a substitution of cement (20% by weight). It is shown in the study that the grey RHA enhanced the compressive strength by 30% due to the lower carbon content of the ash whereas, the black RHA lower the compressive strength by 30% compared to the control specimen.…”

Effect of Selected Nanospheres on the Mechanical Strength of Lime‐Stabilized High‐Plasticity Clay Soils

“…Nanospheres have a particularly high specific surface area and are therefore more involved in chemical reactions [31]. Moreover, the very fine particles of nanospheres may improve the characteristics of soil [37].…”