Impact of Wood Ash on the Properties of Micro Basalt Fiber Cement Mortar

Background

The continuous use of cement has been on the rise. This increase has a significant detrimental effect on the ecosystem. Many studies are being carried out in an effort to find materials that can replace cement in mortar, either fully or partially. These investigations should have solutions that will be able to produce a higher strength and durable mortar than conventional mortar.

Aim

This study aims to present a sustainable structural cement-based material with lower cement content that provides better mechanical and physical properties.

Objective

The goals of this study were to determine the cement-wood ash replacement percentage that resulted in the best compressive and flexural strength on cubes and rectangular beams, respectively, as well as to examine and evaluate the physicomechanical characteristics of the cement-wood ash mortar with and without scattered basalt fiber reinforcement.

Methods

A variety of mortar mixtures were created, each with a different amount (20%, 40%, 60%, 80%, and 100%) of wood ash replacing cement in part or entirely by volume. The effects of scattered chopped basalt fiber and wood ash/cement substitution were tested for strength after 7 and 28 days of cure. On the mortar, tests for density, slump, and water absorption rate were performed.

Results

The result of this research revealed that mortar reinforced with chopped basalt fiber had an improved compressive and flexural strength at defined mixes at 28 days of curing with a maximum compressive strength of 12.58 N/mm². The experimental results suggest 20-40% replacement as the optimum range for cement-wood ash partial replacement. An average increase in density with an increase in sample age as well as the addition of basalt reinforcement was observed with a sample B1 containing 20 percent partial replacement of cement with ash and in the presence of basalt fiber reinforcement, exhibiting the highest density of 2272kg/m³ at 28 days of age contrasting with sample A5, containing 80 percent partial replacement of cement with wood ash. Moreover, sample A5 showed a density of 1824 kg/ m³, the lowest value at 28 days of age.

Conclusion

The study showed improvement in the flexural and compressive strength of the mortar when reinforced with micro basalt fiber. The partial replacement of cement with wood ash in mortar showed an impact on the water absorption rate and strength of the mortar. Hence, this cement-wood ash mortar reinforced with micro basalt fiber can be used in plastering walls or for flooring to improve the properties of the concrete structural members. Additionally, it can also be used in concrete repairs.