Mixture Design of Concrete Using Ultrasonic Pulse Velocity

This article discusses the possibility of using ultrasonic pulse velocity (UPV) as a performance parameter for concrete design. Experimental values of UPV were determined for 68 mix design of concrete with different types of binders. Portland cements with fly ash, blast furnace and silica fume were investigated. All samples had UPV between 4700 and 5400 m/s. The UPV decreases when the w/b ratio increases, although this behaviour is less evident for concrete with silica fume. Also, the UPV is greater at 91 days for all types of binders, when compared with results at 28 days. This is explained due to the formation of more hydrated products inside the concrete over time and because UPV is more difficult to propagate in the void space. It was possible to correlate the compressive strength with the UPV at 28 days, except for the concrete with silica fume. However, the results of these two tests are difficult to correlate at 91 days for all types of binders. This article has shown that it is possible to include UPV in dosage diagrams for some types of binders. The paper proposes empirical models obtained through numerically analysing the dosage diagrams by means of non-linear regressions for estimating the UPV of concrete. The parameters used in these models are usually present in concrete dosing, such as the quantity of aggregates, water-to-binder ratio, compressive strength, and cement content. The correlation coefficient (R2) between the experimental and the calculated UPV was greater than 0.88. Therefore, the inclusion of a non-destructive testing during the concrete design is encouraged. The UPV monitoring can be performed as many times as necessary without causing damage to the structure. © 2019, Iran University of Science and Technology.