TECHNOLOGY
Maintaining concrete strength
Comment contributed by a . b . e .
While admixtures can add strength , the durability of concrete structures can be greatly increased by a proper preventative maintenance and repair programme .
Images by a . b . e .
Products produced by a . b . e . are being used for maintenance work on several N14 highway bridges between the Hartbeespoort / Sandton and Lanseria off-ramps .
Warren Trew , Gauteng sales manager : General Construction of a . b . e . Construction Chemicals , says that the durability of concrete depends largely on undertaking proper preventative maintenance . He points out that many key South African building and civil structures have eroded with age , neglect , misuse , weather factors , rebar corrosion , extraneous loading , and natural disasters . “ Neglecting the need to introduce proper repair and maintenance systems for these structures results in reduced capital value and wastage of resources , which could lead to poor quality of life for communities . With large parts of South Africa currently experiencing devastating drought , the need for adequate maintenance of water reservoirs and dams particularly comes to mind . “ In a sustainable built environment , structural maintenance is nonnegotiable . As soon as a concrete structure is completed , the need for a maintenance programme must start . Maintenance should not be driven simply by the need to correct defects that occur over time , but to avoid these defects in good time ,” Trew states . He says concrete is a durable but not eternal material and will over time deteriorate and require repair or replacement , especially in zones where chloride ingress or carbonation are a reality . Repairing deteriorated concrete and restoring its structural integrity should consequently form part of the initial design — but are frequently resorted to only when emergencies arise .
“ The first step in a successful repair project involves early damage assessment and arriving at a proper diagnosis . The owners should not wait until the concrete shows obvious signs of distress . The most crucial aspect of the repair process is the evaluation stage . To properly repair any damage , it is important to understand what caused the problem and then determine the correct method of repair . “ Experience is vital for the diagnosing and planning for concrete repairs . While there is a high level of expertise that goes into concrete construction , the skills , understanding , and experience required to repair damaged or deteriorated structures are decidedly different from those required to build new structures . That is why it is important to consult reputable suppliers of concrete repair products
24 - CEC April 2018