Concrete, a composite mixture of water, aggregates, cement and sometimes additives, is the most commonly employed man-made building material in construction projects. The quality of concrete is crucial if structures are to be safe and serve the purpose for which they were designed. Consequently, the testing of fresh, hardened and in-situ concrete is vital to ensure that concrete structures comply with specifications and relevant standards. ELE International designs and manufactures a comprehensive range of concrete sampling and testing equipment to meet this requirement in accordance with international standards for both field and laboratory testing.
With high compressive strength and low tensile strength, concrete is usually reinforced with materials such as steel. However, different strengths of concrete are used for different applications. Lightweight, low-strength concrete has good thermal properties and is suitable for sub-screeds and filling redundant voids, whereas high strength concrete is generally specified in large projects - lower floor columns of high-rise concrete buildings and in bridge beams for example. ELE’s concrete testing equipment is designed to ensure that these different types of concrete can be tested to ensure that they meet the specific requirements of each project.
Fresh concrete is tested onsite and in the laboratory using the slump test and air entrainment meters to check the water-cement ratio, air content and workability. It may also be necessary to measure compaction and density, drying, shrinkage and moisture movement. To demonstrate compliance with specifications, concrete mix samples are taken and prepared in moulds as cubes, cylinders or beams. Typically concrete cubes are cured and tested in a manual or automatic concrete compression machine at 7 days and 28 days to assess compressive strength. ELE’s comprehensive range of concrete compression machines are able to test concrete, mortar and cement samples such as cubes, cylinders, flagstones and beams, and accessories are available for testing the flexural and transverse strength of concrete samples.
Concrete cores can be taken from hardened concrete for testing, but Non-destructive Test (NDT) equipment enables the testing of in-situ concrete or concrete samples. ELE provides crack detection microscopes, and a (Schmidt) rebound hammer for measuring surface hardness and penetration resistance. In-situ water permeability equipment is available in addition to ultrasonic test equipment for the inspection of internal condition.