Soil Stabilisation

Ecocem GGBS and GGBS-rich blended cements are suitable technical solutions for your geotechnical works both when looking for soil properties improvement or brownfield remediation cases.

Case Study – Shinfield Studios

Contractor – O’Keefe

Target : Soil Geotechnical properties improvement & limit impact of sulfate swell.

On-site soil samples were recovered from trial holes and assessed:

They appear under the form of mostly grey or brown clay , silty type soils
Organic levels well below 5% (average 1.9%)
TPS values between 0.8% and 1.6%

Test trials were performed to assess impact of Lime+GGBS addition over:

Maximum Dry Density (MDD) at Optimum Moisture Content (OMC)
Linear expansion with time
Soaked CBR value (3 days sealed + 4 days under water)

DESIGN REQUIREMENTS for STABILISED SOIL

CBR Value	Compacted Dry Density
≥ 5%	≥ 95% of MDD

Results & Recipe validation

		Optimum Moisture Content	Maximum Dry Density
Sample 14	+2% Lime	23.5%	1.59
Sample 14	+2% Lime + 1% GGBS	23.3%	1.59
Sample 15	+2% Lime	24.3%	1.57
Sample 15	+2% Lime + 1% GGBS	25.0%	1.57

No impact of GGBS addition/combination to a lime treatment over the on-site soil samples:

Required moisture of the soil to achieve its maximum dry density
Achieved Maximum Dry Density

Small additions of GGBS over your current lime treatment will not affect compaction operation and preparation.

Assessing the linear expansion (TPS swelling risk) after 28 days with variations in Lime+GGBS addition

		Sample 2	Sample 4	Sample 5	Sample 7
TPS		0.85%	1.10%	1.60%	0.97%
Linear expansion after 28 days	+2% Lime	0.20%	1.35%	1.79%	0.72%
	+2% Lime +1% GGBS	0.12%	2.01%	1.40%	0.45%
	+2% Lime +2% GGBS	0.06%	1.38%	1.35%	0.26%

In all cases, the addition of GGBS addition on top of 2% allow for reduction in swelling after 28 days

Final recipe selected for further (on-site) trial: +2% Lime +1% GGBS

		Linear Expansion @7 days	CBR value
Sample 14	None	0.02%	1.7%
	+2% Lime	0.22%	19%
	+2% Lime +1% GGBS	0.07%	27%
Sample 15	None	0.11%	4.5%
	+2% Lime	0.65%	15%
	+2% Lime +1% GGBS	0.13%	24%

All Lime + GGBS treatments on on-site soil samples enabled:

CBR value of largely beyond 5% requirement and above pure Lime
Limited significantly swelling after 7 days compared to pure Lime treatment

BENEFITS

High efficiency of Soil Stabilisation obtained with ECOCEM GGBS.

A Durable and Low-Carbon solution for your geotechnical works.

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