Monitoring strength development of concrete using the wave propagation technique: A practical study

Abstract

Concrete is one of the most commonly used materials in the construction industry for structural members such as slabs, beams, columns and foundations due to its low cost, high durability and long service life. When concrete is freshly mixed it is in a paste form, which eventually develops into a hard solid once it has cured over time. Concrete typically takes 28 days for full-strength development. In bottom-up concrete construction, it is important to monitor the strength development of concrete under curing to ensure the concrete members are strong enough before casting additional structural elements above. In this study, an attempt is made at a construction site to monitor the strength development of concrete under curing with the non-destructive piezoelectric-based wave propagation (WP) technique. The WP technique employs two piezoelectric sensors and offers the capability of real-time monitoring on the strength development of concrete. The pressure wave (P-wave) velocity can be acquired after applying voltage to the sensor. The P-wave velocity can then be related to the strength of concrete at different curing durations. Based on the on-site experimental study, the P-wave velocities correlate well with the compressive strength of concrete from destructive compressive tests. This on-site experimental study shows the applicability of the WP technique for predicting the strength of concrete in a practical application.