Utilization Potential of Glass Fiber and Crumbled Rubber as Subgrade Reinforcement for Expansive Soil

Due to its high potential for volume change, expansive soil is a problematic building material that can cause harm to road infrastructure. The purpose of this study is to examine the effect of glass fiber and rubber on the properties of expansive soil and their suitability as subgrade reinforcement in road applications. For different percentages of glass fiber and rubber in the soil, the Maximum Dry Density (MDD), Optimum Moisture Content (OMC), and CBR were measured. The results demonstrated that the incorporation of glass fiber and rubber improved the soil's properties. With increasing fiber and rubber content, the MDD and CBR increased, while the OMC decreased. In addition, the strength of the reinforced soil was significantly greater than that of the unreinforced soil. The research indicates that the addition of glass fiber and rubber can improve the efficacy of expansive soil as subgrade reinforcement in road applications.   Doi: 10.28991/HEF-2023-04-03-06 Full Text: PD

Aerosol OT Quantity Impacts on Calcium Nitrate Self-Healing Microcapsule Properties Used for Sustainable Construction Applications

This paper is a continuation of a previously published paper on this issue that studied the microencapsulation of calcium nitrate in urea-formaldehyde shell using Aerosol OT (AOT) in hexane solution. The aim of this paper is to determine the quantity of AOT that optimizes microcapsule distribution, diameter, and shell thickness. Different quantities of AOT, namely 0.25 g, 0.50 g, 1.5 g, and 2.5 g were dissolved in 180 g of hexane solution to prepare the continuous phase. A Scanning Electron Microscopy (SEM) was used to characterize the distribution and the diameters of the prepared microcapsules. A Transmission Electron Microscopy (TEM) was used to investigate the microcapsule shell thicknesses. The SEM images have shown that using 0.25 g of AOT may be insufficient to totally polymerize the whole quantity of the core materials into fully independent capsules. On the other hand, using 0.50 g of AOT has shown a uniform distribution and almost complete polymerization of the core material components into distinct microcapsules. Higher quantities of AOT (i.e., 1.50 g and 2.5 g) have resulted in agglomerated microcapsules and nonuniform distributions. The results have also demonstrated that the quantity of AOT does not have a significant impact on the microcapsule diameter. Microcapsule average shell thicknesses were found to decrease by increasing AOT amount up to 0.50 g and to increase again due to the agglomeration witnessed for increased AOT quantity. Accordingly, 0.50 g of AOT was recommended for the preparation of calcium nitrate microcapsules in future research work