Effect of waste rice husk ash from rice husk fuelled brick kilns on strength, durability and thermal performances of mortar

Autor: G.H.M.J. Subashi De Silva, Thusitha Etampawala, S. Vishvalingam
Rok vydání: 2021
Předmět:
Zdroj: Construction and Building Materials. 268:121794
ISSN: 0950-0618
DOI: 10.1016/j.conbuildmat.2020.121794
Popis: Effect of waste RHA, residual ash generated from rice husk fuelled brick kilns, on strength, durability and thermal performances of mortar was investigated. Cement in the mortar was replaced by 0%, 5%, 10%, and 20% of waste RHA. Compressive strength, bulk density, water absorption, porosity, sorption rate, sulfate, acid and alkaline resistance, thermal performance, and microstructural analysis of specimens were examined. Bulk density of control (i.e. 0%) and 20% waste RHA mortar were 2033 kg/m 3 and 1821 kg/m 3, respectively, promising a lightweight mortar by blending waste RHA into the mixture. At 56 days, Strength activity index (SAI) was achieved to be 95% and 85% for 5% and 10% waste RHA mortar, respectively, indicating better compressive strength achievement with waste RHA added mortar. The expansion due to sulfate exposure was reduced by 54% and 70%, for 5% and 10% waste RHA mortar, respectively. Weight loss due to acid exposure was reduced by 45%, 40%, and 25% for 5%, 10%, and 20% waste RHA specimens, respectively. The weight loss due to alkaline exposures was reduced from 3.13% to 2.41% with rising waste RHA level from 0% to 5%. Mortar with 20% waste RHA had a higher temperature difference than the control mortar, indicating that RHA contributed to the reduced thermal conductivity. At 5% waste RHA sample, high counts of CSH was formed, micro-voids were filled, making it a dense structure, which is favorable to achieve improved strength and durability performances.
Databáze: OpenAIRE
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