Quantification of Effective Flow Resistivity for Parametric Assessment of Pervious Concrete by Using Ultrasonic Pulse Velocity Method

Sat, 08 Apr 2023 16:08:54 GMT

The use of nondestructive ultrasonic pulse velocity (UPV) testing to assess the hardened properties of pervious concrete (PC) mixtures is an emerging research area. Further, UPV has been successfully used to determine the effective flow resistivity (EFR) of asphalt concrete and cement concrete pavements. However, no research studies have focused on understanding PC characteristics using EFR. Thus, the major objectives of this study were to assess the suitability of UPV testing for characterizing PC mixtures and to quantify their EFR, which is a measure of the material’s characteristic impedance and is dependent on the mix variables along with porosity. Thirty-six control and sand-modified PC mixtures were prepared with four aggregate gradations, and three levels each of water-to-cement (w/c) and aggregate-to-cement (a/c) ratios. Test results indicated that EFR was significantly dependent on the mix variables, with aggregate gradation being the most influential factor (six and eight times higher than w/c and a/c ratios, respectively). Lower EFR or higher sound absorption capacity was reported for PC with higher porosities. The sand-modified PC mixtures had higher EFR (by 4%–12%) than the control PC, and consequently lower sound absorption capacity, attributed to the presence of mortar that densified the mixes. Further, good-to-excellent correlations were obtained for various PC properties with UPV and EFR, which underscored the potential of UPV in characterizing PC. The major contribution of this research was the development of a simple, fast, and cost-effective approach, which can be suitably adopted as a quality-control test to determine PC mixture properties.

APPLICABILITY AND SIGNIFICANCE OF RHEOMETRIC TESTS FOR RHEOLOGY OF FLUID AND SELF-LEVELING HIGH-STRENGTH CONCRETE

Mon, 08 Sep 1997 00:00:00 GMT

The emergence of new special concretes on construction sites has shown that concretes of the same slump may behave quite differently on the job. For these concretes, one cannot rely on the traditional workability tests for quality control and rheological characterization. It has been claimed that the flow behavior of fresh concrete closely approximates the Bingham model and that at least two parameters are therefore needed to describe its rheology. Thus, rheological measurements must be carried out at not fewer than two shear rates. This study examines the applicability of the Bingham model to fluid and self-leveling high-strength concrete (HSC). Results obtained from a rheometer are compared with results of the standard slump test. Fluid concrete mixtures were investigated that had a water/binder ratio (w/b) of 0.33 and slump values of 200 +/- 20 mm and incorporated proportions of limestone filler, silica fume, and ground silica as partial replacement (by volume) of cement. In addition, self-leveling concrete mixtures (torque viscosity

TRB Publications Index

Quantification of Effective Flow Resistivity for Parametric Assessment of Pervious Concrete by Using Ultrasonic Pulse Velocity Method

APPLICABILITY AND SIGNIFICANCE OF RHEOMETRIC TESTS FOR RHEOLOGY OF FLUID AND SELF-LEVELING HIGH-STRENGTH CONCRETE