Mohammad Jamal Khattak

Bio: Mohammad Jamal Khattak is an academic researcher from University of Louisiana at Lafayette. The author has contributed to research in topics: Compressive strength & Geopolymer. The author has an hindex of 18, co-authored 70 publications receiving 1058 citations. Previous affiliations of Mohammad Jamal Khattak include Michigan State University.

Durability and Mechanistic Characteristics of Fiber Reinforced Soil–cement Mixtures

Abstract: Over the years, field experiments and research information have been collected and studied on the behavior of soil–cement mixtures, and quite a few studies have been conducted for fiber reinforcement in soil–cement mixtures. This research study focuses on the laboratory durability and mechanistic evaluation of soil–cement mixtures reinforced with Processed Cellulose fibers (PCFs) and polypropylene fibers (PFs). Four soil types from various project sites in the state of Louisiana were acquired. Laboratory tests including the durability, unconfined compressive strength (UCS), indirect tensile strength (ITS), and indirect tensile cyclic load tests (ITCTs) were conducted. The results indicated that the mechanistic characteristics of the soil–cement–fiber mixtures were functions of fiber dosage, soil type and curing time. In general, the durability, UCS, ITS and fracture toughness, and resilient modulus values of soil–cement–fiber mixtures either remained the same or were greater than soil–cement mixtures. Mor...

Fatigue and permanent deformation models for polymer-modified asphalt mixtures

Abstract: For the past 2 decades, significant research has been conducted on polymer-modified asphalt (PMA) mixtures. Polymers can successfully improve the performance of asphalt pavements at low, intermediate, and high temperatures by increasing mixture resistance to fatigue cracking, thermal cracking, and permanent deformation. Most of the research has been concentrated on the characterization and relative comparison of neat and PMA mixtures, and little work has been done toward the development of fatigue and permanent deformation models for PMA mixtures. A 3-year study that was sponsored by the Michigan Department of Transportation was conducted at Michigan State University to characterize PMA mixtures. It was found that the rheological and engineering properties of PMA mixtures largely depend on the polymer type and content. The improvements in the fatigue lives and resistance to permanent deformation are mainly due to the improvements in the rheological properties of the binders. Fatigue life and permanent deformation models were developed. These models show that the laboratory fatigue life and permanent deformation are strongly related to the rheological properties of binders and the engineering properties of PMA mixtures.

Engineering Properties of Polymer-Modified Asphalt Mixtures:

Abstract: A large research program sponsored by the Michigan Department of Transportation was designed and completed to evaluate the effect of polymer modification on the various properties of asphalt mixtures. These include the micro- and macrostructural, morphological, chemical, and engineering properties. Some of the engineering properties of the styrene-butadiene-styrene and styrene-etylene-butylene-styrene polymer-modified asphalt mixtures are presented and discussed. The elastic, fatigue, tensile, and permanent deformation properties were investigated at 60, 25, and —5° C. It was found that, for some polymer systems, the fatigue life and the indirect tensile strength increased considerably at 25° C while the elastic properties at -5° C were not affected by the addition of polymer. The implication of this is that the use of some polymer systems in asphalt mixtures enhances their fatigue cracking and rutting resistance without affecting the low temperature cracking potential.