It’s been six years since Concremote first debuted in the Middle East & Africa region, since which time it has become a popular choice for contractors and consultants alike. By accurately measuring the insitu concrete maturity gradient, users are able to assess the earliest time to commence deshuttering, thereby saving precious hours or even days per cycle, and while this is of great benefit to high-rise construction, it becomes less of an asset when dealing with low rise property.
When considering construction methodology and urban planning, they both typically cater to the demands of the environment, for example in cities such as Dubai, which has seen exponential growth over the past two decades, skyscrapers were developed to provide housing for the burgeoning population in order to maximise its footprint for its estimated 3.33 million residents. Just a few hundred kilometres south, and Oman faces a similar challenge in terms of its 4.6 million, except with a far larger area of land, meaning less of a requirement to build up, but rather build out.
One of the things these two places share in common, at least where construction is concerned are the searing summer temperatures which can exceed 50 degrees in July and August. As any engineer will tell you, concrete matures at different speeds depending on several factors, but most prevalently the mass of the concrete being set, the specific mix being used and the outside temperature.
In the case of large masses of concrete, the central temperature will rise quickly in the early stages due to hydration heat and remain so for some time due to its low thermal conductivity. This, however, can become problematic in warmer climes as higher external temperatures typically accelerate the early age strength development, however, reduce the long-term strength development by inducing porosity and increased microcracking in the cement paste.
One of Concremote’s lesser known benefits is its ability to provide valuable data during the planning stages. Thanks to its calibration system, site teams are able to simulate the strength gain and temperature development for each concrete mix and ready-mix plant in advance, meaning there are more options for selecting a concrete mix based on fast strength development vs. high-cost mixtures, or slow strength development vs low-cost mixtures.
Speaking on behalf of Doka Muscat, managing director, Chris Jardine, said, “The effects of temperature early in the life of concrete can strongly influence long-term stability. In general, concrete temperature peaks at 48 hours and remains constant for seven days. The larger the concrete structure, the more heat it will likely generate. Differential temperature, air temperature and concrete mix temperature are all important factors. Monitoring the temperature of concrete during the curing process is a critical factor in making sure the product sets to its full strength and knowing when it is safe to build on.
A great example of this in action was on the Duqm Refinery, a mega project located in the Special Economic Zone of Duqm (SEZAD), about 600 kilometres south of Muscat. As with all major infrastructure projects, ensuring the quality and durability of the concrete structure was essential and by using Concremote to consistently measure the temperature, we were able to avoid issues such as thermal cracking and share the results with the consultant.”
According to concrete experts, there are four primary issues when dealing with high concrete temperatures. An increase in the demand of water and therefore cost, an increased chance of shrinkage leading to cracking, decreased concrete strength after 28 days and an increase for potential corrosion of reinforcements.
“Failure to properly monitor the temperature of mass placements during the heat dissipation phase can result in the mass concrete elements being rejected. Rejected concrete elements usually must be removed at the contractor’s expense.”
Speaking on behalf of Doka MEA, Mark Robertson, business development manager, Concremote, commented; “Real-time performance tracking of strength gain and temperature development of fresh concrete empowers job-site staff to make effective decisions to optimize the construction process for economics and concrete durability. Concremote can and will enable all stakeholders to have accurate and real-time information during the concrete construction phase of their projects. This enables them to make informed decisions based on accurate, up-to-the minute information.”