By Ben du Preez
Hindle Mason Projects (HMP) ensures durable concrete repairs that perform over the long term. Our concrete repair methods, when combined with HMP’s state-of-the-art corrosion protection, significantly prolong the useable life of concrete structures.
The high success rate of our concrete repair projects can be attributed to our thorough processes. To implement suitable concrete repair interventions that are fit-for-purpose, HMP first collects and analyses available information about the structure. This helps to gain a better understanding of its actual condition. For example, we will analyse drawings and specifications, as well as repair and maintenance records over the years.
Once we have a broad understanding of the overall state of the structure, HMP can advance to the next project phase. This entails determining the underlying cause of the degradation via structural analysis.
HMP’s concrete repairs address problems
HMP’s concrete repairs are effective because they solve underlying problems. They do not only address the symptoms.
Working alongside our clients’ engineers, we survey the condition of the structure using various sophisticated techniques. This information enables a professional engineer to determine the remaining service life of the structure. It identifies whether the damage type is mechanical, physical or chemical, oftentimes identified by reinforcement corrosion. The latter remains the leading cause of early degradation of concrete structures. Refer to Reinforcement Corrosion – an overview | ScienceDirect Topics. It is mainly caused by chloride-ion and carbon ingress. However, chemical attack can also be as a result of alkali-aggregate reaction [Aggregate Reaction – an overview | ScienceDirect Topics]. Bacterial exposure and other biological action are also a cause of chemical damage to concrete. Refer to Effect of bacteria on uncracked concrete mechanical properties correlated with damage self-healing efficiency – A critical review – ScienceDirect. Mechanical damage is caused by impacts; overloading; movement; and vibrations. Meanwhile, freeze/thaw action; thermal movement; salt crystal expansion; shrinkage; erosion; abrasion; and wear cause physical damage.
We can then advise our clients on the best management strategy to meet the structure’s future requirements. There may be instances where we recommend simply downgrading the capacity of the structure. In these instances, the structure has not been designed to perform current applications. Even the best structural strengthening will not enable the structure to handle additional loading. There may be situations where structures or parts thereof need to be demolished and rebuilt from the foundation up. They have been allowed to degrade to such an extent that it will be more cost-effective to rebuild as opposed to repairing them.
HMP undertakes quality concrete repairs
However, in most instances, HMP opts to undertake quality concrete repairs either to the entire structure or parts thereof.
The decision to repair a concrete structure is based on an array of factors. For example, we consider the required durability or performance of the structure. Importantly, we also thoroughly assess the health and safety risks during repairs. The ability to execute repairs in operational environments in a healthy and safe manner has always been a key differentiator.
We also consider the possibility of further repair work in the future, including access to and maintenance of the structure. Comprehensive management plans will also define any future required inspection and maintenance over the structure’s lifecycle. HMP also evaluates the probability and likelihood of complete or partial structural failure before recommending repairs.
An array of environmental factors also needs to be contemplated. This includes the structure’s exposure to sun, rain, frost and wind, as well as contaminants, such chloride-ions and carbon. Environmental conditions also have a bearing on the type of concrete repairs undertaken and their duration. For example, noise and dust pollution, as well as potentially harmful systems will need to be managed carefully. A case in point is the responsible use of systems containing volatile-organic compounds. Refer to What are volatile organic compounds (VOCs)? | US EPA.
While it may seem obvious, concrete repairs must always be practical and feasible.
HMP’s concrete repair insights
As a specialist contractor, HMP’s concrete repair insights are often incorporated into the concrete repair design by engineers. This is especially our knowledge of repair systems and their performance in specific applications and environments. HMP is an approved applicator of many quality concrete repair and corrosion protection systems. This enables us to guarantee our workmanship for the maximum available term. In most cases, our material suppliers will also be required to sign-off on our workmanship to ensure that the system was applied correctly.
The concrete repair design philosophy considers the type, causes and extent of the defects. This is in addition to a future maintenance programme and the intended use of the concrete structure. The engineer has not only analysed the long-term performance of the structure. The effect of the selected repair systems and methods on the rest of the structure have also been considered. For example, the extensive preparatory work involved in a typical concrete repair project can cause further damage to the structure.
Thereafter, we can mobilise to site to commence executing the concrete repair design. This while working alongside the engineer and, oftentimes, with technical representatives of manufacturers and suppliers of the repair systems. HMP is effectively the bridge between the design engineer and manufacturers of the repair systems.
HMP’s concrete repair work
HMP’s concrete repair work complies with strict standards. The methods deployed will depend on an array of factors, such as site access and conditions. For example, these will have a bearing on whether we use patch, pour or spray methods. They will also influence the type of surface preparation we undertake. Importantly, the work needs to be undertaken in a health and safe manner throughout.
HMP will also keep accurate records of concrete repairs for future reference at the end of each project. These will detail the type of systems deployed and how they were applied. We will also provide the client with an anticipated new life expectancy of the structure after the intervention. This is in addition to the mode and result of the eventual deterioration of the selected materials. Chalking, embrittlement, discoloration or delamination are signs of deterioration of various repair systems. The client will also want to know when the repairs should be inspected for signs of degradation. This is in addition to remedial work required if there are signs of deterioration.
Ben du Preez is HMP’s Contracts Director