Specimen Size and Shape Effects on the Concrete Properties, Thermal Conductivity and Heat Generation from Hydration for Different Concrete Types

Abstract

The environmental impact, manufacture and the application of concrete have many influences, some of which are influential and complex. Construction engineers are looking for modern ideas and methods that make the building more efficient in terms of functionality, cost, high strength, reduced overloads and increased efficiency of unlimited geometric shapes. The main factor in the improvement and development of concrete structures rely on the engineering characteristics of the substances. The developments in the construction materials, mix proportions, dimensions, mixing, and conditions (temperature) used to enhance the concrete technology, have important impacts on characteristics of concrete strength and heat development manner. The heat generation from concrete reveals the components of concrete materials and mix balances as well as the innovations in structure and environmental circumstances. This research presented an experimental investigation of the significance of the specimen’s shape and the size of the concrete properties durability, thermal conductivity and heat generation. Cylinders, prisms, and cubes of different sizes and shapes will be used. This research concluded that the effect of molds shape and size decreased when the (strength in compression, splitting tensile strength, flexural strength, and concrete density) increasing, that’s mean for ultra-high-strength concrete the difference is much smaller. The concrete hydration due to heat increases with increasing of the concrete strength and size, and the difference in heat transfer with the increasing of specimen’s size decreasing with increasing of concrete size. It is completely identified that the deformation and intensity of reinforced concrete beams depend on the size of the beam. Effect of concrete types (normal 26 MPa, high 46 MPa, and ultra-high-strength concrete 61 MPa) on the design of reinforced concrete beam was studied with three different depth (170, 155 and 150 mm). Results revealed that high strength and ultra-high-strength concrete was able to substitute for the reduction in beams size with the same strength. For concrete that is high or ultra-high-strength a reduction in the beam depth of about (8.82%) and (11.76%) compared to the normal concrete beam where achieved.