EVALUATION OF SEMI-FLEXIBLE PAVEMENT PERFORMANCE | ||||
| Journal of Al-Azhar University Engineering Sector | ||||
| Article 18, Volume 15, Issue 54, January 2020, Page 100-111 PDF (385.72 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/auej.2020.73146 | ||||
 View on SCiNiTO | ||||
| Authors | ||||
| Momtaz Mohamed Gamal Othman1; Zeinab Salah El-Din Hussein2; Ahmed Ibrahim Abu El-Maaty3 | ||||
| 1General Authority of Roads, Bridges and Land Transport, Cairo, Egypt | ||||
| 2Building Materials Research and Quality Control Institute at the National Center for Housing and Building Research, Cairo, Egypt | ||||
| 3Roads and Airports Engineering Department, Faculty of Engineering, Menoufia University, Menoufia, Egypt | ||||
| Abstract | ||||
| This study aims at characterization and design new special type of asphalt mixture having lower asphalt content and higher rutting resistance to be used in paving surface layers at heavy loads areas. To achieve this objective, grouting technique of permeable open graded asphalt mixtures was used. Such type of pavement is called as a semi-flexible pavement (SFP) or grouted macadam (GM). Different compaction efforts were used to achieve the required percent of connected air voids between the bitumen coated aggregates. Crushed silica limestone, crushed sand, and filler were used to prepare highly permeable asphalt mixtures. Asphalt contents of these mixes were determined theoretically and It was ostensibly examined by the laboratory. Marshall molds representing open graded mixtures were prepared and grouted using a grout composed of ordinary Portland cement (OPC) as well as a mixture of some concrete additives with different ratios. Choosing the suitable grout mixture depended on the flow time, flexural and compressive strengths for lab-produced grout prisms. Measuring Marshall stability, Marshall flow, and indirect tensile strength test were conducted on grouted asphalt mixes to identify their properties. The same tests were conducted on crushed silica limestone open graded mix of 2C gradation (Egyptian Standards for Roads) for comparison purposes. Analyzing the study results, positive effect of grouting open graded mixes was concluded using a mixture of OPC, fine sand, silica fume and superplasticizer. The required bitumen content for surface layers was decreased by percent between 27% to 37% compared with traditional dense asphalt mixtures. The resistance of rutting for grouted mixes was increased through increasing stability and indirect tensile strength by about 3 times and more compared with traditional open asphalt mixtures. | ||||
| Keywords | ||||
| Semi-Flexible Pavement; Grouted Macadam; Open Graded Mixture; Ordinary Portland Cement; Silica Fume; Fly Ash; Marshall Stability | ||||
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