Aggregate and Sand Producers Association of South Africa (Aspasa) and the Southern Africa Readymix Association (Sarma) has cautioned that Building collapses in South Africa could become more prevalent should there be an escalation in the use of inappropriate or substandard building materials in construction projects.
- incorrectly-specified" materials could lead to immediate or future building failures as a result of increased loads or owing to the corrosion of foundations from surrounding soil conditions
- the role of the engineer is, therefore, critical in establishing soil conditions and geological conditions, as well as in establishing the specification of suitable stones and sands to mix with the cement
- the size of the aggregates used in concrete, or the composition of sand used, can play a role in the future strength of a structure.
- the entry of unlicensed and "unscrupulous" quarry and mine operators in the sand and aggregate supply industry in South Africa is creating confusion
- at surface level, the aggregates may look the same, but they may have completely different chemical compositions when examined under the microscope
- when readymix concrete is being used, design engineers should ensure that the materials are being appropriately procured from Aspasa members and that readymix suppliers are registered and approved by Sarma.
- when mixing concrete on site, the project manager should oversee material use and ensure that mixtures are correct and ratios are as specified