Journal of Materials in Civil Engineering

The potential use of waste recycled glass in concrete as recycled glass sand (RGS) and pozzolanic glass powder (PGP) was examined in this study. No major difference was found in compressive strength of concrete with the presence of RGS as sand replacement. While, the compressive strength of concrete reduced by 16 and 10.6% at 28 and 364 days respectively when 20% of Portland cement was replaced by PGP. The potential expansion of concrete due to alkali-silica reaction (ASR) was monitored according to the procedure of British Standard BS 812 Part 123:1999. As a siliceous material, the use of RGS as sand replacement in concrete possesses high risk of ASR expansion. Therefore, cracks were observed when RGS was used as sand replacement in concrete without any precautions to minimize this risk. Different materials were used as ASR suppressors to mitigate the potential risk of ASR, such as: ground granulated blastfurnace slag, metakaolin, PGP, and lithium nitrate $\left({\text{LiNO}}_3\right)$ . The expansion associated with ASR was significantly reduced when the ASR suppressor was used in concrete.

The spectral analysis of surface waves (SASW) method is a nondestructive testing method of pavements based on the dispersive characteristic of seismic surface waves. The method can provide the thickness and stiffness of pavement layers. One of the more complex aspects of the SASW method is an iterative process to estimate the pavement parameters, called the inversion procedure. In this paper, the feasibility of completely automating the inversion process and substituting it with artificial neural network (ANN) models was explored. A number of different ANN models were developed using various ANN training strategies. To improve the performance of some ANN models, a sequential modeling technique was implemented. In the sequential modeling, some pavement parameters are estimated first from an initial set of ANN models, which is then the input to subsequent ANN models to estimate other parameters of interest. Furthermore, the performance of the ANN models was evaluated using a number of well-characterized pavement sections. The results illustrated that ANN models could estimate the upper layers’ parameters so well that they could replace the inversion process. The ANN models for other layers were capable of generating robust initial estimates for a well-constrained formal inversion that can be readily automated.

In this study an experimental investigation on shear behaviors of longitudinally reinforced lightweight aggregate concrete (LWC) beams made with sedimentary lightweight aggregate (LWA) without shear reinforcement was carried out and compared with companion normal-weight concrete (NWC) beams. The sedimentary LWA was a product of fine sediments excavated from the bottom of the Shih-Men Reservoir in Taiwan through proper air drying and sintering processes. A total of 24 simply supported beams were designed for shear failure with a two-point bending system. The primary variables of the investigation include concrete compressive strengths of 23, 43, and 53 MPa and ratios of shear span $\left(a\right)$ to effective depth $\left(d\right)$ , $a/d$ , of 1.5, 2.0, 2.5, and 3.0. The measured shear strengths at failures for all tested beams were recorded and carefully compared against each other. In addition, to assess the validity of the obtained test data, the test results were also compared with those obtained using the present ACI 318 Code equations and Rebeiz’s equations for shear strength. The comparisons demonstrate that the obtained shear strengths of LWC and NWC beams are within an acceptable range of the ACI Code. This investigation concludes that sedimentary LWA is recommendable for structural concrete applications.

The flowable fill is a self-compacting cementitious material used primarily as an alternate backfill in lieu of compacted soil. In general, from the applications point of view, the flowable fill mixtures can be divided into two categories: removable fills (mixtures that require future excavation) and nonremovable fills. The specifications for the removable type of flowable fills typically limit both the minimum and the maximum 28-day compressive strengths, thus increasing the time needed for completion of the approval process. This paper presents set of accelerated flowable mixture approval requirements which can be performed at earlier ages (3 and 14 days) and are based on blow count number from the lightweight dynamic cone penetrometer (DCP). These requirements can be used as an alternative to the 28-day compressive strength testing and are considered for adoption by the Indiana Department of Transportation. They were developed based on both, laboratory and field tests which included 14 different mixtures. The DCP-based approval is preferred, as (unlike the compressive strength) the test can be performed in situ and thus better represents the characteristics of flowable fill.

A laboratory study was undertaken to evaluate the effectiveness of different percentages of hydrated lime, class C fly ash (CFA), and cement kiln dust (CKD) as soil stabilizers. Cylindrical specimens were compacted and cured for 28 days in a humidity room having a constant temperature and controlled humidity. At the end of the curing period, specimens were tested for resilient modulus $\left(M_r\right)$ , modulus of elasticity $\left(M_E\right)$ , and moisture susceptibility using tube suction test. The study revealed that the values of $M_r$ , $M_E$ , and unconfined compressive strength (UCS) for the stabilized specimens increased with the increase in the amount of the stabilizing agent. It was also found that the increase in $M_r$ , $M_E$ , and UCS values varies with the type of stabilizing agents. The CKD-stabilized specimens exhibited a higher increase in $M_r$ , $M_E$ , and UCS values than the corresponding values of lime- and CFA-stabilized specimens. Additionally, CKD-stabilized specimens exhibited the least moisture susceptibility in terms of lowest dielectric values as compared to lime- and CFA-stabilized specimens.

In the past, gravimetric corrosion data for fasteners exposed to treated wood has been reported as a percent weight loss. Although percent weight loss is a valid measure of corrosion for comparing identical fasteners, it can distort the corrosion performance of fasteners with different geometries and densities. This report reevaluates a key report on the corrosiveness of wood treated with chromated copper arsenate (CCA) and ammoniacal copper arsenate (ACA) and converts the previous data into corrosion rates. In addition, similar experiments were run in wood treated with alkaline copper quaternary (ACQ). Comparison of the corrosion rates reveals ACQ treated wood is more corrosive than CCA treated wood for every metal. The corrosion rate of aluminum was found to be lower than both hot-dip galvanized steel and electroplated galvanized steel in ACQ, ACA, and CCA treated wood. In ACA and ACQ treated wood, the electroplated galvanized fastener had a lower corrosion rate than the hot-dip galvanized fastener.

Portland cement pervious concrete (PCPC) is increasingly used across the United States, and this has prompted various entities to begin the process of developing standardized test techniques. A major issue with placing PCPC is the inconsistencies in concrete workability between mixtures developed in the laboratory and in the field. It is therefore urgent to properly determine workability of pervious concrete and to ensure that the designed concrete mixtures are suitable for particular compaction methods and field conditions. This paper describes a new test method for characterizing PCPC workability—the gyratory compaction test method. A modified Superpave gyratory compactor (SGC) is employed in the present study. Two PCPC workability parameters are defined from the gyration compaction curve: (1) workability energy index, which describes initial concrete workability and (2) compaction densification index, which describes the resistance of the tested mixture to further compaction. The effects of binder content and water-to-cement ratio as well as effect of concrete mixing time on PCPC workability are studied. Based on the test results, values of the workability parameters for concrete with various degrees of workability are specified.

The low viscosity of asphalt concrete at $T>135°\mathrm{C}$ is necessary for the construction and compaction process of high-quality asphalt concrete layers. Whereas the continuous increase of viscosity with decreasing temperature is desirable for the reduction of permanent deformations during warm periods, so-called top-down cracking may occur in the course of temperature drops during cold periods. In order to explain the complex viscoelastic properties of asphalt concrete, a multiscale model is proposed. Hereby, the viscoelastic behavior of bitumen serves as input and the effect of air voids and aggregates is investigated. The viscous properties of bitumen are identified, using the bending-beam rheometer and the dynamic-shear rheometer, providing access to the viscoelastic material response for different temperature and loading regimes. With the rheological properties of bitumen at hand, the viscoelastic properties of mastic, mortar, and asphalt concrete are determined using continuum micromechanics, employing the elastic-viscoelastic “correspondence principle.” The creep properties of asphalt concrete obtained from the presented mode of upscaling from the bitumen to the asphalt scale is validated by means of cyclic tests and static uniaxial creep tests.

This paper addresses a user-friendly test method to measure as-received aggregate coefficient of thermal expansion (CoTE) using dilatometery. A dilatometer can accommodate materials of different size, shape, and density and can measure representative CoTE within approximately a 24-h period. The dilatometer test was validated by establishing favorable comparisons between the dilatometer measured CoTE and the CoTE determined by alternative techniques for selected metals, minerals, and aggregates. This method has a great potential to be considered as a laboratory method for measuring the CoTE of aggregate materials. The new dilatometer-based test method can be used by state DOTs and other specifying agencies (1) to determine the CoTE of an aggregate source and to assess the variability of the average CoTE as a measure of quality control and (2) to design mixture proportions for achieving the required concrete CoTE as a function of aggregate CoTE. This test allows for the improvement of the characterization of concrete thermal behavior, as a function of its constituent properties, leading to better performance prediction.

Porous frictions courses (PFCs) are characterized by high percent air voids content, and are widely used as pavement surface drainage layers. This paper presents details on the laboratory investigation performed on evaluation of properties of PFC mixes using the Superpave gyratory compactor. It also, provides a brief review of the latest specifications related to standard practices for mix design and the uses of these mixes adopted by various agencies. Major differences were observed in the design gyrations $\left({\text{N}}_{\text{design}}\right)$ and the design aggregate gradations. In this study, six gradations (G) were investigated with binder contents (BCs) ranging between 4.0 and 5.0% by mass of the total mix, for various gyration levels (N). The effect of N, G, and BC on the volumetric properties, unaged abrasion loss, permeability, and the permanent deformation characteristics of PFC mixes were investigated. The experimental results were statistically analyzed to identify the major influencing factors and their significance.

Cavitation damage in hydraulic structures may reduce the useful life of structures, leading to periods of operation interruption. Frequently the risk of erosion is accepted and the damages provoked are minimized with the use of appropriate cavitation resistant materials. The objective of this work was to develop and test an apparatus that promotes a cavitating jet in order to evaluate cavitation damages in concrete specimens. The experimental study indicated that this apparatus is adapted for the evaluation of cavitation resistance in concrete specimens. The principal advantage of the apparatus is the requirement of a small assembly area. Expenses with energy are reduced, due to the short exposure operation time.