Concrete Crack Repair with Polymer Modified Mortars: The Status Quo in the South African Construction Industry and the Way Forward

In recent years, concrete repair has become an integral part of the construction industry. With the vast quantity of concrete used in the South African construction industry over the past 100 years, one can expect an increase in repair and rehabilitation requirements during the extended lifecycle of exposed concrete structures. Crack repair, re-profiling of spalled areas and surface sealing with polymer related materials forms the bulk of such repair and rehabilitation operations. Due to the complexity of these projects and the variety of professionals and other stakeholders involved from the diagnostics to the implementation phase (specialists consultants, contractors, suppliers and owners of the structures), considerable problems seem to have surfaced to ensure cost-effective but sustainable and durable outcomes. It has been found that in many concrete repair projects, the responsibility for the repair work, adequate quality control and the assessment of successful patch repairs are not fully embraced by the various stakeholders.This concern has led to the research as reported in this paper. The research entailed a series of questionnaires drawn up specifically for the four different stakeholder sectors of the concrete repair industry. The results indicate that, although there is agreement that concrete repair is a highly specialized field, there is not enough training in the correct use of the repair materials, nor enough knowledge regarding the diagnostics or material specification and selection processes. Knowledge on polymer modified mortar are also minimal. These problems are compounded by inadequate quality control and lack of ongoing monitoring of patch repair failure. The paper concludes with suggestions on the way forward.