Open-graded friction course (OGFC) asphalt mixture, usually used to construct porous pavements, represents one of the materials supporting low-impact development (LID) philosophy due to its use of coarse aggregate gradation. Using such mixtures brings several benefits related to safety, environment and economy. Alas, coarse, open-graded skeleton of OGFC mixtures is prone to failure, particularly raveling and stripping. Continuous traffic loading and the environmental impacts give hand in hand to further increase the potential for failure, hence higher pavement maintenance and rehabilitation costs. Application of different types of modifiers has proved effective in mitigating failure potential. The most common modifiers are polymers, fibers and anti-stripping agents. Aiming at minimizing the costs and maximizing the lifespan while considering sustainability, the study was to investigate the effect of using a recycled stabilizing material as an asphalt modifier on the performance of OGFC asphalt mixtures. Recycled Low-Density Polyethylene (R-LDP) was adopted in this investigation. Changes in mixture air void, porosity, draindown, permeability, rut depth, moisture damage and abrasion loss were observed to evaluate the effect. Compared with unmodified asphalt samples, R-LDP modification increased mixture air void, porosity and permeability by 15%, 10% and at least 40%, respectively. Also, it noticeably contributed to reducing rut depth, moisture damage and abrasion loss (both unaged and aged) by 31%, 20% and at least 40%, respectively. More significantly, it almost eliminated the draindown problem. Incorporating R-LDP proved effective in upgrading OGFC mixture properties to an acceptable level required by most specifications.
An open-graded friction course (OGFC) is a special type surface layer of traditional Dense Graded Hot Mix Asphalts (DGHMA) pavement that is increasingly being used around the world due to its various benefits, such as, frictional, safety and environmental, etc. In this research, selective laboratory OGFC properties were statistically modeled depends on mix design inputs for two purposes or aims; mix inputs significant and prediction the OGFC properties according mix inputs. Principally, Indirect Tensile Strength (ITS), water sensitivity (TSR), and permeability (K) were selected from mechanical, durability, and volumetric properties, respectively as an output property; they represent the dependent variables for each model. While, fillers as conventional mineral filler or Ordinary Portland Cement (CMF, or OPC), binder content (BC), and polymer content (SBS) are represented inputs or the independent variables for all models. The generated models offered a vital achievable tool for prediction (e.g., their R² are 0.781, 0.82 1and 0.820, respectively, for the mentioned model’s properties), also it helped to scale the significant of each independent variable (e.g., filler type significantly affect water sensitivity properties, its correlation was 0.752). This study reveals that the statistical modeling is achievable and offers a dynamic tool to describe the characteristics and performance of OGFC mixture in term volumetric, mechanical and durability properties.
Sustainability has recently gained a high profile in many fields. Construction, due to its huge demand to materials, is one of the important targets. More than 95% of roads are paved with hot mix asphalt (HMA). Production of HMA using virgin materials consumes a lot of energy and contributes to the emission of a considerably large volume of CO 2 . Therefore, the replacement of virgin materials with waste and extending material life is of considerable value. Half-warm bituminous emulsion mixture (HWBEM) is a cold bituminous emulsion mixture subjected to a moderate heating energy before the compaction process. This study aims to evaluate the extent of enhancement in HWBEM crack resistance using a low energy heating technique (i.e., microwave) where virgin fine aggregates within the mixture were replaced with waste crushed glass. In addition to the measurement of volumetric properties and mixture sensitivity to moisture damage, crack related tests of indirect tensile strength test (ITS), cracks resistance test (Ideal-CT test), fracture energy (G f ), cracking resistance index (CRI) and toughness index (TI) were conducted to evaluate mixtures tensile strength. Test results showed that the procedure followed to prepare HWBEM containing waste crushed glass worked out and prevented cracking failure. It was concluded that adopting ITS is not sufficient to reflect all mixture behavior phases when resistance to the tensile cracking is the concern, as it depends on the peak load only. Other indices, such as CT-index, depend on more than one parameter and reflect a reasonably more realistic evaluation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.