With the construction of a new Asda store and associated retail units on a new site in Abbey Wood, Filton near Bristol, SMR products were used to create the load bearing vehicle areas for all the associated retail units.
What was previously a field needed to be turned into a large and stable and permanent vehicle parking area. There was also a requirement to re-use the existing ground materials as much as possible in the construction of the sub-base layers. This would avoid the need to import aggregate which would also mean that none of the excavate material would have to be transported offsite and disposed of in costly landfill.
The methodology chosen for this project was to bring a Wirtgen WR240, a purpose built higher performance/ high efficiency cold recycling and soil stabilisation vehicle onsite and undertake all work in-situ.
SMR’s proprietary stabilisation material is initially evenly spread over the area before being mixed with the existing soil to the required depth by the Wirtgen to cerate the required sub-base layer. This is subsequently levelled and compacted to achieve the required stability and load bearing performance before a bitumen Emulsion was sprayed over the entire compacted area to weather proof it and provide an appropriate wearing layer.
To achieve a minimum load bearing performance of 30% CBR using traditional methods an estimated 630 lorry movements would be required to transport around 6300 tonnes of excavated tonnes to landfill with a further 6300 tonnes of primary aggregate and sub-base material being re imported for use on the site. This would create around 3.22 tonnes of CO2 as a result of the lorry movements, plus all associated transportation cost. The purchase of the new materials would also need to be factored in along with the landfill taxes.
By using the in-situ methodology, based on applying SMR material, no more than 10 lorry movements (creating a negligible 0.05 tonnes of CO2) were be required to achieve a load bearing performance of between 30% CBR up to 100%+ CBR.
Significant reduction in vehicle movements: By eliminating the requirement to send existing material to landfill and replace it with new imported aggregate over 630 vehicle movements were avoided.
Project delivered in a timely way: By opting for the SMR in-situ methodology the project was completed in a fraction of the time that would have been needed had traditional extract and replace methods had been used.
Zero material to landfill: Not only were the transportation costs removed from the project but so were all landfill taxes and the cost of purchasing and transporting new materials to site.