The environmental impact of the construction industry is a concern and research in the development of eco-friendly construction materials should be a high priority. New construction materials or even just improving conventional construction materials is imperative for a more sustainable built environment. The objective is to both develop new construction materials but also reduce the environmental impact of currently used construction materials. The activities are within the field of alternative masonry units, including material development, structural testing, determining suitable specifications and lasting implementation on a large scale. Work is also done on researching more eco-friendly cement-based binder and natural fibres in a cement-based matrix. Alkali activated materials are also investigated as an alternative for conventional concrete.
Mechanical and Environmental Specifications for Alternative Masonry Units
Student: Wibke de Villiers (PhD)
Supervisor: Prof WP Boshoff
Standards for conventional masonry units (CMU's), namely burnt clay, calcium silica and concrete, are well established and in common use. However, directly applying these established performance requirements of CMU's to alternative masonry units (AMU's) is inappropriate for a number of reasons, including the significant differences in material properties between CMU's and AMU's. Therefore, to enable the introduction of AMU's into the Category 1 housing market, minimum specifications for their application need to be determined. It is proposed that nonlinear finite element modelling of bonded AMU walls, validated by laboratory testing, can be used to determine the minimum mechanical and environmental performance requirements for AMU's.
Determination of the Mechanical Performance Requirements of Alternative Masonry Units
Student: JP Jooste (M.Eng)
Supervisor: Mrs WI de Villiers
To facilitate the introduction of alternative masonry (AMU's) into the Category 1 housing market, standards and specifications of their minimum required mechanical performance should exist. Previous work has determined acceptable testing methods and much of the mechanical properties of three types of AMU's, namely alkali-activated concrete, cement-stabilised earth and adobe blocks. These properties will be used to perform non-linear finite element analyses of single storey bonded walls. Walls of each type of AMU will be modelled such that their geometry conforms to SANS 10400-K and the loads applied to SANS 10160:2011. These analyses aim to determine the minimum required mechanical performance of the walls, which will ultimately be used to determine the minimum required mechanical performance of the units themselves.
Investigating the Structural Response of Single Storey Alternative Masonry Walls
Student: Prince Shiso (M.Eng)
Supervisor: Mrs WI De Villiers
To assist the development of alternative masonry units (AMU's), full-scale masonry wall tests are performed on wall specimens constructed using four different types of AMU's respectively. These tests include the simulation of wind and seismic loading. They aim to validate the results of a finite element analysis of the four wall types and to validate the assessment methods performed on the masonry units which will provide an indication of the masonry units' behaviour within a structural masonry wall.
Creating a Low Embodied Carbon Concrete with Conventional Concrete Properties
Student: Michael Diekmann (M.Eng)
Supervisor: Prof WP Boshoff & Dr R Combrinck
During the production of cement, a large amount of carbon dioxide is produced, making cement and concrete unfavourable in terms of its impact on the environment. The aim of this research is to create a concrete with a smaller carbon footprint by designing a concrete with a reduced cement content, yet still exhibiting conventional fresh and hardened concrete properties and ready for use as a conventional concrete. This will be achieved by using supplementary cementitious materials, admixtures and optimal packing of aggregates.