Contract awarded to T&M Specialists for Stabilization / Solidification in Hong Kong - Various Locations
Stabilization / Solidification Contract in Hong Kong
Solidification has been identified as the preferred method for treating soils contaminated with heavy metal (lead). The method involves immobilization of the contaminant within the soil matrix by mixing cement in with the soil to impart physical and/or chemical changes that result in locking the lead in the solid structure and reducing the rate of its migration through leaching.
Following delineation of the extent and depth of the excavation required, contaminated soils shall be excavated, placed on hard standing with run off protection and screened to segregate soil from debris, rock fragments and other materials and to break soil clumps into sizes allow effective mixing with solidifying agents.
The mixing equipment identified to perform the solidification of heavy metal contaminated soils is an excavator. An excavator was chosen for its capability to the desired specified material combination by mixing cement and water as conditions may require. The uniformity of the mix is particularly critical. Infinitely variable and wide ranging feed adjustments of cement and water allow proportioning of components such that the specification requirements are achieved.
A predetermined amount of cement and water shall be added to the untreated soil, which shall be mixed uniformly within skips. The mixing shall be undertaken for the minimum duration able to ensure a homogenous mixture.
The soil cement mixture would be formed into blocks and solidified then tested to confirm if the mix meets the target of (i) Toxicity Characteristic Leaching Procedure (TCLP) Test ; (ii) Unconfined Compressive Strength (UCS) Test as stipulated in the contract.
By working to support the Client, other areas are now under consideration for similar works, which broadens the service disciplines that T&M can offer.
This approach to the Client is successfully working on current T&M projects from Canada, North America, South America and Indonesia building a strong relationship and continuous ongoing support expanding into other works within T&M capabilities on these Projects.