Large mass concrete pours are becoming more and more prevalent as project ambitions grow. When completing mass concrete pours there are a number of important factors that need to be considered and addressed, these include:
- Understanding that once the concrete is poured some factors e.g. rate of hydration and peak temperatures can no longer be controlled, so it is important to get things like mix designs, cementitious blends, concrete temperatures, right before you start.
- Once placed the focus moves to thermal monitoring and managing temperature differentials between the core and surface of the elements.
Thermal management plan are critical components of mass concrete pours because they help prevent thermal cracking, failure of the structures, claims and costs.
When concrete hydrates, heat is generated this causes the concrete to expand. As hydration slows and the heat dissipates, the concrete contracts again. The surface tends to cool down faster than the core, which retains heat for longer. Therefore, the surface contracts while the core remains expanded, resulting in tensile stresses if significant enough, thermal cracking will occur, severely compromising the structure. Peak temperatures also need to be managed.
What Is a Thermal Management Plan?
A thermal management plan for a mass concrete pour is essentially a plan to ensure that all appropriate measures are taken minimize the risk of concrete element experiencing thermal cracking. These include:
How Can You Monitor Temperatures?
- Mix design
- Optimizing cement contents.
- Pure Portland cement mixes generates more heat than cementitious blends containing fly ash and/or slag, look at replacing Portland cement with fly ash and/or slag.
- Reducing concrete placing temperatures using chilled water, ice, etc.
- Construction requirements:
- Appropriate insulation methods.
- Comprehensive real time monitoring of concrete temperatures.
With ConXedge’s real-time concrete temperature monitoring system, you will have complete certainty about the thermal activity in your mass concrete pour.
Our single-use conXone sensors,robust single channel conXsensors and four-channel ConXagents – which use consumable thermocouples or digital sensors – can be installed strategically within the concrete to measure concrete temperatures accurately.
You can then monitor the readings from these sensors in real time using our sophisticated data communications in our conXagents or single-channel conXstations data transmitters. These data loggers have wireless mobile technology that enables them to save and transfer the data to the cloud.
Our cloud-based ConXedge data management system then uses the data to automatically inform you if critical limits or warning thresholds are at risk of being breached and help you make informed analyses and generate reports, among other functions. All of this from anywhere at any time.
No thermal control plans for mass concrete pours would be complete without a ConXedge thermal monitoring system, which will ensure your complete your project with absolute confidence. Get your ConXedge system by contacting us