A Practical Approach for the Estimation of Strength and Resilient Properties of Cementitious Materials

Abstract

Cementitious stabilization of granular soils has been proven to be a cost-saving option for the use of materials with marginal quality in the construction and rehabilitation of pavement structures. The orthogonal load distribution capacity of the Cement-Stabilized Materials (CSM) is typically characterized by Unconfined Compressive Strength (UCS), Indirect Tensile Strength (IDT), and Resilient Modulus (Mr) tests in the laboratory. The aforementioned parameters and properties are integral components of the analysis and design of pavements with stabilized layers. Time and budget constraints make it impractical for many state agencies to complete the full laboratory characterization protocols to determine all the design input parameters. Therefore, in many cases, the design engineers opt out of laboratory testing and primarily rely on past experience and engineering judgments to assign design input parameters. Such an approach compromises the reliability of the pavement life predictions, and can potentially incur unforeseen costs to the traveling public. This study was designed to bridge this gap by developing a series of statistically robust relationships between the laboratory achived data to provide an estimate of the design input parameters. To accomplish this objective, 570 stabilized cylindrical specimens were prepared and subjected to UCS, IDT, and submaximal modulus tests at three strength ratio levels. Subsequently, the relationships between the IDT, UCS, and resilient modulus at small-strain and intermediate strain levels were developed in this study. Such relationships can serve as a valuable means for the estimation of the tensile and compressive strength of the CSM for pavement design.

Initial Hypotheses for Modeling and Numerical Analysis of Rockfill and Earth Dams and Their Effects on the Results of the Analysis

“…With regard to the fact that the value of the bulk modulus of water is equal to 2e9 Pa under real conditions, parametric examinations have been conducted on bulk modules from 1e7 to 1e8 Pa; therefore, the equivalent bulk modulus can be selected. On the other hand, since the bulk modulus values also rely on con ning pressure [15], the bulk modulus could also be increased in the dam height. e graphs of Figure 7 indicate di erent status of R u for di erent equivalent bulk modulus.…”

Review of Emerging Additive Manufacturing Technologies in 3D Printing of Cementitious Materials in the Construction Industry

“…This can occur when the delivery pipe does not have enough supply materials coming out of the nozzle. However, the shrinkage cracks can be solved by adding fibers such as glass fiber or polypropylene fibers and slightly increasing the w/c ratio (Rashidi et al, 2018) or by adding a wire (308LSo stainless steel) to increase the tensile strength of the printed objects (Laghi et al, 2018). Another limitation that is faced when printing the concrete was the oscillations experienced by joints 4 and 6 of the industrial robot when the robot approaches singular configurations.…”

Ground Improvement Using Dynamic Compaction in Sabkha Deposit

“…EsmaeilpourShirvani et al [1] carried out a series of large-scale direct shear tests on the shear strength characteristics of reinforced sand-clay soil mixed with natural fibers, and it was found that the shear strength parameters of the reinforced sand-clay mixture were significantly improved. Rashidi et al [2] proposed a series of statistical relationships between unconfined compressive strength, indirect tensile strength, and resilient modulus for the analysis and design of pavement structures based on a large number of mechanical and durability tests using cementitious stabilized granular soil. Sabkha ground might be improved by soil stabilization or ground reinforcement, but dynamic compaction is applied at the job site because dynamic compaction is an economical method for improvement of sabkha deposit and the most appropriate method to crush low-strength crystals, such as crystalline salts comprising gypsum, anhydrite, and halite.…”