Study On Dust Monitoring And Hazard Degree Evaluation Of Building Construction

Constructional fugitive dust is one of the great factors which make construction worker suffer from occupation disease and lead to city air pollution. Due to the particularity in the different stages of construction, the distribution regularity of constructional fugitive dust, fugitive dust composition and the fugitive dust hazard degree is different. In order to accurately grasp the constructional fugitive dust distribution regularity and hazard degree, the whole stages of construction is divided into three parts, the earthwork stage, the main body of construction stage, the interior decoration stage.And based on the actual situation about construction site, the constructional fugitive dust is divided into silicious dust, cement dust, gypsum dust and wood dust by the different of the fugitive dust composition.The dust monitoring plan is made by the characteristics of the different construction stages of dust emission and the actual situation of construction site. The CCHG1000 direct-reading dust concentration measuring instrument is used as the monitoring tool. 369 groups of dust concentration data are got from 2 construction site in Beijing. According to the monitoring data: the average dust concentration of backfill reached 1.08 mg/m3 and the access of large vehicles reached 1.00 mg/m3 in earthwork stage, the average dust concentration of form disassembling phase reached 1.49 mg/m3 and wood processing shed reached 4.78 mg/m3 in the main body of construction stage, the average dust concentration of putty project reached 5.19 mg/m3 and steel connection reached 3.35mg/m3 in interior decoration stage.Based on the occupational exposure limits for hazardous agents in workplace stander(GBZ2—2007)and hazardous degree classification of workplace with dust stander(GB/T5817—2009), combined with the monitoring data, the different stages and areas of fugitive dust hazard degree are evaluated and got these conclusions: in the earthwork stage, the earthwork backfilling and the entrance for large vehicles are the highest fugitive dust hazard degree; in the main body of construction stage, the wood barrack is the highest fugitive dust hazard degree; in the main body of construction stage, the fugitive dust hazard degree of form disassembling reached 25% which is the highest in the whole construction stages, in the interior decoration stage, the steel connection is the highest Fugitive dust hazard degree in whose all measuring positions.Based on above, the control method of each stage of fugitive dust pollution is put forward. In the earthwork stage, the road hardening should be speed up, and use the sprinkler. Forth dedusting is be used to reduce dust in winter in case of road frozen; in the main body of construction stage, wood barrack should be strengthen ventilationed and cleaned up anytime especially before the form disassembled to reduce dust pollution; in the interior decoration stage, the water soluble strong material should be used instead of the poor ones to reduce dust and the water spray should be used to reduce the dust pollution in steel connection punch.