Register now After registration you will be able to apply for this opportunity online.
This opportunity is not published. No applications will be accepted.
Investigating sustainable building technologies for rural Malawi: Optimizing cement ratios for compressive clay bricks
The purpose of this proposed research is to investigate a research questions related to one of our previously published works on alternative building materials in Malawi.
In Mahdjoub et al (2021) we evaluated the performance of post-consumer waste glass as a coarse aggregate within burnt clay bricks, in order to assess the feasibility for the recovery of this waste material from dumped stocks within Chembe, a rural tourism resort destination in Malawi. Using a brick design and testing methodology, which could be replicated within a rural African context, we tested a range of glass additions (both quantity and size of particle) for compressive strength and water absorption properties. Our results suggest that waste glass can function as a performance enhancer, with positive effects on compressive strength observed at up to 10% crushed waste glass content. Firing the bricks, however, is extremely inefficient, as it relies on an increasingly scarce resource (wood), and is a focus of one our current projects, designed to modify current firing practices.
On a recent field visit to Chembe we connected with a local organisation which owns a machine to make compressive clay bricks. Utilising a mix of 85% clay and 15% cement, they are currently making a very strong brick that does not require firing. However, cement is a very expensive input in Malawi, and in Chembe in particular.
Data
The Civil Engineering Department at the Malawi University of Business and Applied Sciences (MUBAS) has undertaken workshop testing using a brick making machine similar to the one at Chembe, and with clay sourced from the community. Specific data to be analysed includes:
- Soil characterisation of clay material
- Compressive strength testing results from compressive brick samples with the following concrete ratios: 16%, 14%, 12%, 10%, 8%, 6%, 4%, 2%, 0%.
- Flexular strength testing results from compressive brick samples with the following concrete ratios: 16%, 14%, 12%, 10%, 8%, 6%, 4%, 2%, 0%.
- Water absorption testing results from compressive brick samples with the following concrete ratios: 16%, 14%, 12%, 10%, 8%, 6%, 4%, 2%, 0%.
In Mahdjoub et al (2021) we evaluated the performance of post-consumer waste glass as a coarse aggregate within burnt clay bricks, in order to assess the feasibility for the recovery of this waste material from dumped stocks within Chembe, a rural tourism resort destination in Malawi. Using a brick design and testing methodology, which could be replicated within a rural African context, we tested a range of glass additions (both quantity and size of particle) for compressive strength and water absorption properties. Our results suggest that waste glass can function as a performance enhancer, with positive effects on compressive strength observed at up to 10% crushed waste glass content. Firing the bricks, however, is extremely inefficient, as it relies on an increasingly scarce resource (wood), and is a focus of one our current projects, designed to modify current firing practices. On a recent field visit to Chembe we connected with a local organisation which owns a machine to make compressive clay bricks. Utilising a mix of 85% clay and 15% cement, they are currently making a very strong brick that does not require firing. However, cement is a very expensive input in Malawi, and in Chembe in particular.
Data
The Civil Engineering Department at the Malawi University of Business and Applied Sciences (MUBAS) has undertaken workshop testing using a brick making machine similar to the one at Chembe, and with clay sourced from the community. Specific data to be analysed includes:
- Soil characterisation of clay material - Compressive strength testing results from compressive brick samples with the following concrete ratios: 16%, 14%, 12%, 10%, 8%, 6%, 4%, 2%, 0%. - Flexular strength testing results from compressive brick samples with the following concrete ratios: 16%, 14%, 12%, 10%, 8%, 6%, 4%, 2%, 0%. - Water absorption testing results from compressive brick samples with the following concrete ratios: 16%, 14%, 12%, 10%, 8%, 6%, 4%, 2%, 0%.
Thus, the specific aim of this study would be to determine an optimal ration of clay and concrete which would require the minimum amount of concrete, while still producing a strong (based on compressive strength and flexural strength) and weather-resistant (based on water absorption) brick.
Thus, the specific aim of this study would be to determine an optimal ration of clay and concrete which would require the minimum amount of concrete, while still producing a strong (based on compressive strength and flexural strength) and weather-resistant (based on water absorption) brick.
ETH for Development (ETH4D) aims to develop innovations that are directly relevant to improving the livelihoods of people in low-resource settings and to educate future leaders in sustainable development.