Evaluating the effect of geomorphology on quality of construction materials with emphasis on aggregates in Qalehshahin catchment

Geomorphological Landforms and processes are of the most significant parameters that affect the distribution and quality of construction materials especially aggregates. The purpose of this research is to evaluate the effect of geomorphological landforms and processes in the formation and quality of construction materials with emphasis on aggregates in Qalehshahin catchment. Qalehshahin catchment with a drainage area of 169. 8 km² is an upstream subcatchment of Alvand basin in Kermanshah province، and is part of Folded Zagros structural zone. To achieve the purpose of this study، Geomorphological landforms and processes were recognized by Quickbird satellite images as well as field works. Result of this study represents that alluvial fans and taluses have large amounts of weathered and crushed rocks and sediments that can be used as construction materials. To determine the quality of aggregates، 14 samples of aggregates in alluvial fans and taluses were obtained and Impact Value test of aggregates has been done based on sieve No. 8. Results of aggregate Impact Value tests show that means of mentioned test in taluses، new alluvial fans and old alluvial fans are 9. 835، 8 and 9. 47 percent respectively that show appropriate quality of all samples of aggregates. This study represents that، in spite of appropriate quality of aggregates of both taluses and alluvial fans، old alluvial fans have aggregates with lower quality because of long term weathering، whereas the quality of aggregates in new alluvial fans، with fresh and less weathered sediments، is rather better. Overall، result of this study reveals that the evaluation of geomorphological forms and processes has an important role in recognizing and determination of quality of construction materials especially aggregates.