Pervious concrete is a stormwater management practice used in the United States, Europe, China, Japan, and many other countries. Yet the design of pervious concrete mixtures to balance strength and permeability requires more research. Sphere packing models of pervious concrete were used in compressive strength testing simulations using the discrete element method with a cohesive contact law. First, three mixtures with varied water-cement ratios (w/c) and porosities were used for model development and validation. Next, an extensive database of simulated compressive strength and tested permeability was created, including 21 porosities at three w/c. Analysis of the database showed that for pavement applications where high permeability and strength are required, the advised porosity is 0.26 to 0.30, producing average strengths of 14.4, 11.1, and 7.7 MPa for w/c of 0.25, 0.30, and 0.35. The model can guide the mixture design to meet target performance metrics, save materials and maintenance costs, and extend the pavement life.

Beam specimens of polypropylene fiber-reinforced concrete (PPFRC) with 1.3 vol. % having three different sizes, 100 x 100 x 400 mm, 150 x 150 x 530 mm, and 200 x 200 x 650 mm, were tested under four-point bending tests to investigate the flexural behavior (flexural and post-cracking strengths). The beam specimens were quarried from PPFRC slabs to evaluate the influence of the fiber orientation and distribution and the concrete casting and loading directions on the flexural behavior. The test results show that the difference in the fabrication methods of specimens considerably affected the flexural behavior. The flexural cracking strength was accompanied by the size effect and the post-cracking strength, significantly decreased when compared with standardized prism specimens; however, the post-cracking strength was not sensitive to the size effect. Furthermore, the pavement thickness of PPFRC was compared with that of plain concrete with the calculation using the post-cracking strength.

Lack of understanding of the compaction mechanism, both in the laboratory and field, could result in significant underestimation or overestimation of the roller-compacted concrete pavement (RCCP) performance. The literature (1987 to 2022) depicts that there are numerous techniques to design RCCP in the laboratory; however, which method could closely simulate the field compaction is not fully explored. The present paper critically reviews the fundamental parameters affecting the strength characteristics of RCCP when compacted with different compaction mechanisms in the laboratory and attempts to rank the compaction methods based on the field performance. Also, recommendations are made on how to fabricate the specimens without having much impact on the considered compaction technique. The techniques that have been considered are the vibratory hammer, vibratory table, modified Proctor, gyratory compactor, and special compactors such as California kneading compactor, Marshall hammer, and duplex roller. Based on the present review, future research prospects are outlined to improve the performance of RCCP.

This study tested the effect of using taconite as an aggregate replacement in concrete. Taconite is a by-product from iron ore mining that has the potential to be used in concrete production as a coarse and/or fine aggregate. Replacing the aggregate in a concrete pavement with taconite could decrease the demand for increasingly scarce high-quality aggregates. The mechanical properties of concrete made with only fine, only coarse, or both fine and coarse taconite aggregates were tested. Properties tested include compressive, flexural, and tensile strength; elastic modulus; and coefficient of thermal expansion. All concretes made with taconite coarse and fine aggregate, either alone or in combination, produced concrete with acceptable mechanical properties for use in paving. The use of taconite coarse aggregate increased all mechanical properties tested, while the use of taconite fine aggregate had mixed effects on mechanical properties, but values of all properties tested remained within normal ranges. Fresh concrete properties were also tested, and taconite was found to decrease workability. This work shows that both coarse and fine taconite aggregates have the potential to be used as viable aggregates for concrete.

Interlocking concrete block pavement (ICBP) is one of the pavement types adopted worldwide. The influential parameter of ICBP is comparatively more, which includes the geometric parameters of the interlocking paver blocks such as the size, shape, thickness, strength, and laying pattern of the blocks, and the gradations of the jointing and bedding sand. Other than the wearing surface, the thickness and properties of the bedding sand, base, and subgrade also play a vital role in the deflection properties of ICBP. The objective of the present study is to analyze the influence of block thickness, base thickness, and granular layer thickness on the deflection behavior and stress distribution of ICBP. The block thicknesses used for this study are 80, 100, and 120 mm; the bedding sand thicknesses are 30, 50, and 70 mm; and the base thicknesses are 150, 300, and 450 mm. The experimental work is carried out using the laboratory plate load test to determine the deflection and stress distribution of ICBP. Numerical analysis is also employed to simulate laboratory testing. The study attempts to find the most influential factor and the optimized parametric value for attaining lower deflection using Design-Expert software. The test results conclude that the thicknesses of the block and granular layer play an imperative role among the considered parameters.