At ECT (Environmental Chemistry Testing Laboratories), we provide specialist BS 1881 hardened concrete testing to support forensic investigation, quality assurance, compliance assessment and dispute resolution across the construction sector.
BS 1881 is the recognised British Standard for testing hardened concrete and comprises multiple parts covering chemical composition, durability indicators, and material performance. Our laboratories offer a comprehensive suite of BS 1881 chemical analysis, coupled with in-house methods and other industry standards, delivering reliable, defensible data for engineers, consultants, contractors and asset owners.
What Is BS 1881 Concrete Testing?
BS 1881 sets out standardised laboratory methods for assessing hardened concrete, rather than fresh or in-situ concrete. These tests are commonly used to:
- Verify cement content and mix design
- Investigate structural or durability issues
- Assess compliance with specifications
- Support technical disputes or insurance claims
- Evaluate long-term performance and degradation
By analysing hardened concrete samples, ECT can determine original mix proportions, , water content and chemical characteristics that influence strength and durability.
Our BS 1881 Hardened Concrete Testing Services
ECT provides a full range of BS 1881 testing, including the following analyses:
Cement Content Determination
Using state-of-the-art instrumental techniques, we offer UKAS-accredited determination of cement content of hardened concrete.
This analysis helps confirm whether concrete meets specification requirements and whether adequate cement was used during production
Alkali Content Analysis
Alkali levels are critical in assessing the risk of alkali–silica reaction (ASR) and long-term durability issues. Our testing includes results for:
- Sodium Oxide (Na₂O) Content
- Potassium Oxide (K₂O) Content
- Equivalent Sodium Oxide (Na₂O)
These results support durability assessments and forensic investigations into cracking or expansion.
Capillary Porosity (Water Cement Ratio)
Understanding the original water content of concrete is key to assessing strength and durability. Our services include:
- Original Total Water/Cement Ratio
- Capillary Porosity – evaluating permeability and long-term durability
These tests help determine whether excess water was used, which can compromise strength and increase porosity.
In addition to our 1881 testing, we can offer testing to in house methods and other industry recognised standards:
Chloride Content Testing
The presence of chloride can significantly impact the viability of concrete. Using a UKAS accredited methodology we can determine:
- Acid soluble Chloride by Mass of sample
- Acid soluble chloride by mass of cement
Sulphate Content Testing
The presence of sulphate can significantly impact concrete durability. ECT provides sulphate analysis using our UKAS accredited laboratory method:
• Sulphate (SO₃) by Mass of Sample
• Sulphate (SO₃) by Mass of Cement
These tests help identify risks of sulphate attack and assess compliance with exposure classifications.
HAC Identification
We assess the presence of High-Alumina Cement (HAC), which is critical in older structures or where unexpected strength loss is suspected. Identifying HAC supports safety assessments and structural decision-making.
Carbonation
Durability-related testing includes:
· Depth of Carbonation – assessing protection of steel reinforcement
These analyses are particularly important for ageing structures and exposure-related investigations.
Other Properties
ECT provides additional analysis of hardened concrete, including:
· pH in Hardened Concrete
· Carbonate Content (Alkalinity)
· Water Content
These parameters support corrosion risk assessments and structural durability evaluations.
Applications of Chemical Testing of Concrete
Our hardened concrete testing services are widely used for:
- Structural investigations and failure analysis
- Verification of mix design compliance
- Durability and service-life assessments
- Insurance, legal and contractual disputes
- Asset management and refurbishment planning
Why Choose ECT for Chemical Concrete Testing?
ECT combines specialist construction chemistry expertise with rigorous quality systems to deliver results you can rely on. Clients choose us for:
- Comprehensive accredited testing capability
- Experienced laboratory analysts
- Clear, technically robust reporting
- Practical interpretation of results
- Responsive turnaround times
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Trusted Chemical Concrete Testing Expertise
Accurate analysis of hardened concrete is essential for understanding performance, compliance and long-term durability. ECT's concrete testing services provide the detailed insight required to support confident technical and commercial decisions.