The feat of processing clean sand to bring to Cao Lanh highway construction site

Sand mixed with many impurities cannot be used for the construction of the Cao Lanh - An Huu expressway, component project 1, section through Dong Thap province, but the contractor is still trying to handle it to ensure there is enough sand for construction during the day to complete loading by the end of this year.

Sand mixed with many impurities

Mr. Pham Thanh Nam, sand mine manager, VNCN E&C Construction and Engineering Investment Joint Stock Company, said that the sand mine in the area on Tien River, in An Hiep and An Nhon communes, Chau Thanh district, is the third sand mine out of four sand mines granted by Dong Thap province to the contractor for direct exploitation to serve the construction of Cao Lanh - An Huu expressway, component project 1 section passing through the area.

The sand mine in An Hiep and An Nhon communes, Chau Thanh district is the third of four sand mines granted by Dong Thap province for the Cao Lanh - An Huu expressway, component project 1.

The sand mine covers an area of ​​18.02 hectares, with a total reserve of approximately 674,953 m3. Of which, the permitted reserve of sand for exploitation is 420,000 m3. The sand mine exploitation period is 6 months (from August 2024 to February 2025), and the environmental restoration period to close the mine is 6 months.

Sand mining is allowed to be done to a depth of minus 17m. Workers work from 7am to 5pm every day, no mining at night. Sand mining capacity does not exceed 2,570m3/day and does not exceed 77,100m3/month.

However, the amount of sand the contractor gets each day is only 1,100m3 of sand/day. The reason is that this sand mine has up to 62% impurities and the sand is mixed with mud and mud. Currently, the total amount of sand the contractor has exploited at this sand mine is 75,272m3 of sand, all of which is brought back to serve the construction of the highway.

"In highway construction, all criteria must comply with regulations, so with sand mines containing many impurities like this one, the contractor must perform additional processing steps to ensure the sand meets standards before being pumped to the construction site," Mr. Nam added.

The contractor worked hard to process

The contractor proactively handles impurities to ensure that every day there is enough 11,700m3 of sand to serve the construction of the Cao Lanh - An Huu expressway, component project 1, section through Dong Thap province after 4 sand mines are exploited.

The contractor must carry out the overflow discharge, handle impurities, and ensure the quality of sand before pumping it to the construction site.

Accordingly, to handle impurities, at the sand mine, the contractor arranged 2 scrapers (bucket capacity 3.5m3), workers directly exploited sand and loaded it onto the barge. Next, the barge was filled with sand, the contractor drove it to the construction site.

Here, before the sand is pumped to the construction site, the contractor arranges a team of about 10 people to carry out the spillage. Specifically, each sand barge has holes drilled for drainage.

The contractor pumps water onto the barge carrying sand to overflow the hold. From here, impurities including mud and silt will overflow through the holes in the hold, and the sand will settle at the bottom of the barge.

The spillage stage is carried out until the sand grains are visible to the naked eye, then the contractor will send a specialist to inspect. The sand will be checked to ensure the correct quality before being pumped to the construction site to serve the highway construction according to regulations.

"According to calculations, such spillage costs 30% more than normal sand mining.

However, due to the urgent nature of the work, the contractor is carrying out this additional step to ensure the construction progress of the Cao Lanh - An Huu Expressway, component project 1, section through Dong Thap province," said a representative of VNCN E&C Construction and Engineering Investment Joint Stock Company.

Overflow discharge and impurity treatment cost the contractor 30% more to ensure the quality of the sand.

Dong Thap Province Traffic Construction Investment Project Management Board (investor) said that the construction progress of component project 1, Cao Lanh - An Huu expressway, section passing through the province, up to this point has reached about 45%.

The Cao Lanh - An Huu Expressway starts at the intersection with the My An - Cao Lanh Expressway in Cao Lanh District, Dong Thap Province. The end point is at the intersection with the Trung Luong - My Thuan Expressway in Cai Be District, Tien Giang Province.
The scale of the completed phase cross-section meets the standards of a four-lane highway. The cross-section of phase 1 is divided into four-lane investment scales, with a roadbed width of 17m and an operating speed of 80km/h.

Source: https://www.baogiaothong.vn/ky-cong-xu-ly-cat-sach-dua-ve-cong-truong-cao-toc-cao-lanh-an-huu-1922411111813282.htm