Diatomaceous earth aggregates based composite masonry blocks for bushfire resistance

Abstract

Purpose

This paper presents the details of a research study on developing composite masonry blocks using two types of mixes, conventional and lightweight mix, to enhance their fire/bushfire resistance and residual compressive strength.

Design/methodology/approach

Composite masonry blocks (390 × 190 × 90 mm) were fabricated using conventional cement–sand mix as the outer layer and lightweight cement–sand–diatomite mix as the inner layer. Material properties were determined, and all the mixes were proportioned by the absolute volume method. After 28 days of curing, density tests, compression tests before and after fire exposure and fire resistance tests of the developed blocks were conducted, and the results were compared with those of conventional cement–sand and cement–sand–diatomite blocks.

Findings

Developed composite blocks satisfy density and compressive strength requirements for loadbearing lightweight solid masonry units. Fire resistance of the composite block is –/120/120, and no cracks appeared on the ambient side surface of the block after 3 h of fire exposure. Residual strength of the composite block is higher compared to cement–sand and cement–sand–diatomite blocks and satisfies the loadbearing solid masonry unit strength requirements.

Practical implications

Composite block developed in this research can be suggested as a suitable loadbearing lightweight solid masonry block for several applications in buildings in bushfire prone areas.

Originality/value

Limited studies are available for composite masonry blocks in relation to their fire resistance and residual strength.

Citation

Ariyaratne, I.E., Ariyanayagam, A. and Mahendran, M. (2022), "Diatomaceous earth aggregates based composite masonry blocks for bushfire resistance", Journal of Structural Fire Engineering, Vol. 13 No. 1, pp. 118-141. https://doi.org/10.1108/JSFE-07-2021-0047