The meticulous process of cleaning and transporting sand to the Cao Lanh expressway construction site.

The sand, mixed with many impurities, is unsuitable for construction on the Cao Lanh - An Huu expressway, component project 1, the section passing through Dong Thap province. However, the contractor is still making efforts to process it in order to ensure a sufficient quantity of sand for daily construction and complete the load testing by the end of this year.

Sand mixed with many impurities

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

The sand mine located 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 Lan - 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 this, the permitted reserve for leveling sand is 420,000 m³. The sand mining period is 6 months (from August 2024 to February 2025), and the environmental remediation and restoration period before mine closure is 6 months.

The sand mine is permitted to be exploited to a depth of 17m below ground. Workers are allowed to work from 7:00 AM to 5:00 PM daily, with no nighttime mining. The sand mining capacity must not exceed 2,570 m³/day and 77,100 m³/month.

However, the contractor only obtains 1,100 cubic meters of sand per day. This is because the sand mine contains up to 62% impurities and is mixed with mud and silt. Currently, the total amount of sand extracted by the contractor from this mine is 75,272 cubic meters, all of which has been used in the construction of the expressway.

"In highway construction, all criteria must comply with regulations. Therefore, with sand mines containing many impurities like this one, the contractor must carry out an additional processing step to ensure the sand meets standards before it can be pumped to the construction site," Mr. Nam added.

The contractor handled it meticulously.

The contractor proactively handles the removal of impurities to ensure a sufficient supply of 11,700 m3 of sand per day for the construction of the Cao Lanh - An Huu expressway, component project 1, the section passing through Dong Thap province, after the four sand mines are put into operation.

The contractor must carry out the spillage and treatment of impurities and sand to ensure quality before pumping them onto the construction site.

Accordingly, to handle impurities, at the sand mine, the contractor deployed two dredgers (with a bucket capacity of 3.5 m³), ​​and workers directly extracted sand and loaded it onto barges. Next, the barges were filled with sand, and the contractor transported it to the construction site.

Here, before the sand is pumped onto the construction site, the contractor assigns a team of about 10 people to carry out the overflow discharge process. Specifically, each barge carrying sand has drilled holes for water drainage.

The contractor pumps water into the barge carrying sand, causing it to overflow. From there, impurities including silt and mud will spill out through the holes in the hull, while the sand settles at the bottom of the barge.

The spillage process continues until the sand particles are visible to the naked eye, at which point the contractor sends a specialist to inspect them. Only after the sand is inspected and confirmed to meet quality standards is it allowed to be pumped onto the construction site for highway construction, as per regulations.

"According to calculations, such spillage incurs an additional cost of 30% compared to normal sand mining."

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

The contractor incurs an additional 30% cost for spillage and impurity treatment, ensuring the sand meets construction quality standards.

According to the Dong Thap Provincial Project Management Board for Investment and Construction of Transport Works (the investor), the construction progress of component project 1 of the Cao Lan - An Huu expressway, the section passing through the province, has reached approximately 45% to date.

The Cao Lanh - An Huu Expressway begins at the intersection with the My An - Cao Lanh Expressway in Cao Lanh District, Dong Thap Province. Its end point intersects with the Trung Luong - My Thuan Expressway in Cai Be District, Tien Giang Province.
The cross-section of the completed phase meets the standards of a four-lane highway. The cross-section of phase 1 of the investment is also four lanes, 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