Coal tar,a by-product from the destructive distillation of coal in coking oven,is widely used in road engineering for its excellent adhesion and fuel resistance properties,especially for pavement surface treatments in...Coal tar,a by-product from the destructive distillation of coal in coking oven,is widely used in road engineering for its excellent adhesion and fuel resistance properties,especially for pavement surface treatments in gas stations and airports. However,coal tar has a high Polycyclic Aromatic Hydrocarbons (or PAHs) content,which makes it toxic. In 1985,the International Agency for Research on Cancer (IARC) has proved that coal tar is carcinogenic to humans. Research showed that Coal Tar-based Sealers (CTS) contribute to the majority of PAHs pollution in the water environment.Because of this environmental concern,CTS are not allowed in many developed countries in the USA and Europe. In contrast,coal tar is still used for road engineering in China and is even used increasingly.This paper gives a literature review on the general information and research about environmental concern of using coal tar in road engineering. Based on the review,some possible alternatives to replace coal tar are described. These alternatives include nano-clay/epoxy modified bitumen/bitumen emulsion and waterborne polyurethane/epoxy resin,which are environmental friendly. They have the potential to perform as well as CTS,and even better in some special applications.展开更多
文摘Coal tar,a by-product from the destructive distillation of coal in coking oven,is widely used in road engineering for its excellent adhesion and fuel resistance properties,especially for pavement surface treatments in gas stations and airports. However,coal tar has a high Polycyclic Aromatic Hydrocarbons (or PAHs) content,which makes it toxic. In 1985,the International Agency for Research on Cancer (IARC) has proved that coal tar is carcinogenic to humans. Research showed that Coal Tar-based Sealers (CTS) contribute to the majority of PAHs pollution in the water environment.Because of this environmental concern,CTS are not allowed in many developed countries in the USA and Europe. In contrast,coal tar is still used for road engineering in China and is even used increasingly.This paper gives a literature review on the general information and research about environmental concern of using coal tar in road engineering. Based on the review,some possible alternatives to replace coal tar are described. These alternatives include nano-clay/epoxy modified bitumen/bitumen emulsion and waterborne polyurethane/epoxy resin,which are environmental friendly. They have the potential to perform as well as CTS,and even better in some special applications.
