Understanding Durability Problems with Dolerite in Roads in South Africa  

作　　者：Akhona Futshane Philip Paige-Green Joseph K. Anochie-Boateng Akhona Futshane;Philip Paige-Green;Joseph K. Anochie-Boateng(Smart Mobility, Royal HaskoningDHV, East London, South Africa;Department of Civil Engineering, Tshwane University of Technology, Pretoria, South Africa;Department of Civil Engineering, University of Pretoria, Pretoria, South Africa)

机构地区：[1]Smart Mobility, Royal HaskoningDHV, East London, South Africa [2]Department of Civil Engineering, Tshwane University of Technology, Pretoria, South Africa [3]Department of Civil Engineering, University of Pretoria, Pretoria, South Africa

出　　处：《World Journal of Engineering and Technology》2022年第3期574-592,共19页世界工程和技术（英文）

摘　　要：Dolerite is one of the most widely used road pavement construction materials in South Africa and is classified as a basic crystalline rock. The variable performance of road pavements constructed with such rocks in South Africa has frequently been linked to the durability of the freshly crushed dolerite which can undergo rapid deterioration in service. This poor durability affects the life cycle of the road as they can fail prematurely. The prevailing conditions under which rapid deterioration of dolerite occurred on the road are somewhat contradictory. The objective of this study was to provide insight into what influences rapid deterioration in dolerite when used in the base course of road pavements. The evaluation was completed by conducting surveys, field investigations and laboratory experiments comprising mineralogical analyses and engineering tests. Surveys were done to identify the investigation sites. Field investigations comprise visual condition assessment of road pavement surface and pavement structure using test pits. Field investigations were followed by a sampling of material from the identified investigation sites for laboratory material testing. Laboratory testing included standard engineering soil tests and specialised techniques for mineralogical analysis. Two approaches for durability investigations were followed. For each approach, two samples were used (control sample and investigated sample), and the results of the sample investigated were compared with the control sample results. Findings from both approaches were compared. An interesting finding was that, contrary to conventional wisdom, not all of the dolerites investigated contained discernible smectite contents.Dolerite is one of the most widely used road pavement construction materials in South Africa and is classified as a basic crystalline rock. The variable performance of road pavements constructed with such rocks in South Africa has frequently been linked to the durability of the freshly crushed dolerite which can undergo rapid deterioration in service. This poor durability affects the life cycle of the road as they can fail prematurely. The prevailing conditions under which rapid deterioration of dolerite occurred on the road are somewhat contradictory. The objective of this study was to provide insight into what influences rapid deterioration in dolerite when used in the base course of road pavements. The evaluation was completed by conducting surveys, field investigations and laboratory experiments comprising mineralogical analyses and engineering tests. Surveys were done to identify the investigation sites. Field investigations comprise visual condition assessment of road pavement surface and pavement structure using test pits. Field investigations were followed by a sampling of material from the identified investigation sites for laboratory material testing. Laboratory testing included standard engineering soil tests and specialised techniques for mineralogical analysis. Two approaches for durability investigations were followed. For each approach, two samples were used (control sample and investigated sample), and the results of the sample investigated were compared with the control sample results. Findings from both approaches were compared. An interesting finding was that, contrary to conventional wisdom, not all of the dolerites investigated contained discernible smectite contents.

关 键 词：DOLERITE Crushed Stone Road Pavement CLIMATE DETERIORATION Performance 

分 类 号：P58[天文地球—岩石学]