In this section, we look at the various tests conducted in our lab, each designed to ensure the highest quality of our concrete products.
From slump testing to resistivity and absorption tests, we use a spectrum of sophisticated methods to guarantee the workability, strength, and durability of concrete produced with CarbonCure.
1. Slump Testing
The concrete slump test measures the consistency of fresh concrete. It involves placing freshly mixed concrete into a slump cone, consolidating it, and then observing how much it slumps after the cone is lifted. The slump value is crucial for ensuring the concrete's workability.
Slump cone used in slump test
2. Air Content Test
This test uses a pressure meter to measure the air content in fresh concrete. By releasing compressed air into a concrete sample and measuring the pressure changes, we can assess the amount of air voids — or bubbles — which is essential for the durability and quality of concrete.
Pressure meter used in air content test
3. Isothermal Calorimetry
Isothermal calorimetry tracks the heat of hydration of fresh concrete, paste, or mortar samples. The heat released during the hydration of the sample produces a thermal power curve which shows the rate of heat evolution over time. This test helps in assessing the impact of admixtures, determining set times, and understanding hydration reactions.
Isothermal calorimetry machine
4. Cylinder Testing
Cylinders are cast from fresh concrete and cured. For initial curing, the cylinders are covered with a plastic tarp, wet burlap, and a second plastic tarp on top of the burlap to retain the moisture. Cylinders are demoulded after 24 hours, labeled, and stored in curing tanks filled with saturated lime water for future testing, including compressive strength tests.
Cylinders being cast for future testing
5. Compressive Strength Testing
This test measures a cylinder's ability to withstand axial loads without breaking or failing.
Conducted at various intervals after casting (24 hours, 7 days, 28 days), compressive strength testing ensures the concrete meets the specified design requirements and industry standards, and ensures the safety, quality, and durability of the concrete used.
Compressive strength testing machine
6. Resistivity Testing
The resistivity test assesses how well concrete resists electrical current. The test is conducted by placing the probes of a resistivity meter against the side of the concrete cylinder. The meter will apply a known voltage across the probes and measure the resulting current. Lower values indicate good electrical conductivity, whereas higher values indicate less conductivity. It is a key indicator of the concrete's corrosion resistance and overall durability.
Concrete resistivity meter
7. Absorption Testing
This test determines the water absorption capacity of aggregate. The test is conducted by soaking the aggregate in water for 24 hours. The aggregate is then dried to saturated surface dry (SSD) conditions and weighed. It is then dried to oven-dry conditions and weighed again.
Absorption testing is crucial for batching concrete and adjusting water-cement ratios.
8. Carbon Sulfur Analysis
Carbon analyzer used in carbon sulfur analysis
We use a carbon analyzer to measure carbon content in samples, which is essential for understanding CO2 mineralization in our concrete.
Samples are sieved through a 75-micron sieve and run through the carbon analyzer, where they are combusted at high temperatures of more than 2,000°C. The gasses released through combustion are analyzed for their carbon content. With increasing CO2 doses, we expect to see increased carbon content in the samples.
Our lab's advanced equipment and testing capabilities demonstrate CarbonCure's commitment to innovation and excellence. By continuously investing in the latest technology, we ensure the highest standards of quality and safety in our products.