Declan Gavigan, a PhD student from NUI Galway’s College of Engineering and Informatics and the Ryan Institute, recently received the Top Young Engineers’ Award. He was awarded the prize for a paper he presented on ‘Strength and durability performance of stabilised soil block masonry units’ at the recent International Association of Bridge and Structural Engineering (IABSE) Conference.
This conference attracted 120 delegates from around 30 countries and included sessions on Sustainable Development and Structural Engineering; Structural Engineering and Renewable Energy Sources; Smart Structures, New Materials and Construction Techniques.
Dr Jamie Goggins, Chartered Engineer and Principle Investigator for this research project at NUI Galway, comments: “Declan’s paper on ‘Strength and durability performance of stabilised soil block masonry units’ is an important document in the research into stabilised soil blocks or SSBs as they are commonly known. Although there is ample literature on the application of SSBs in tropical countries, their potential use in a European climate has not been fully investigated. Declan is part of an NUI Galway Sustainability and the Built Environment research group, which is currently investigating the feasibility and suitability of SSBs for use in a European context through extensive testing in terms of durability, strength and appearance.”
Stabilised soil blocks are cost-effective masonry blocks formed by compressing a suitable mixture of soil, cement and water into a mould. These masonry units have a low impact on the environment, as their main component, the soil, is often sourced directly from the site of construction. SSBs are extensively used in the construction of both structural and non-structural elements in many developing countries. SSBs have less negative impact on the environment than alternative masonry technologies, such as clay fired bricks or concrete masonry blocks. The most commonly-used stabiliser used in the manufacture of SSBs is Ordinary Portland Cement (OPC), which is their most expensive and energy-intensive ingredient. Replacing OPC with alternative waste materials and by‐products is a cost‐effective process, and their use in SSBs can benefit the environment, especially where disposal to landfill is the alternative.
The ability of blocks to resist prevailing rain, wetting and drying cycles, freezing and thawing cycles, and chemical attack are critical if there are to be applicable in a European climate. The extensive laboratory studies carried out as part of this research projects indicate that SSBs have adequate durability for typical use in the construction of buildings in Europe. In addition, the research has shown that SSBs containing waste materials and by-products as cement replacements can have adequate, and sometime superior performance to specimens containing OPC only as a stabiliser.
On the other hand, utilising waste products in the manufacture of the blocks such as pulverised fuel ash (pfa) from peat-fired power plants have been shown to reduce the performance of SSBs. As an output from this research project, the development of a comprehensive code of practice and design guidelines on the manufacturing and use of SSBs is envisaged to aid the future commercial development of SSBs.
This research project is associated with the priority thematic area ‘Sustainability and the Built Environment’ of the Ryan Institute at NUI Galway.