Test Page
Our petrographers are experts in cementitious materials, construction technology, and the science behind concrete deterioration. Our laboratory is fully equipped for microscopy, chemical analysis, mechanical testing, and durability evaluations.
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Condition Surveys
Rehabilitation of older buildings requires visual assessment by experienced professionals. However, these surveys cannot always determine causes of cracking or deterioration. Petrography is an extension of the visual survey at a finer resolution and this can be supplemented by chemical and physical tests to quantify salt loads or critical material properties.
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Aggregate Evaluations
Aggregate is not an inert ingredient in concrete. Unstable components in natural stone sources can result in aggressive deterioration. Highbridge uses petrography and x-ray diffractometry to identify deleterious constituents either in preproduction or as part of a forensic study of failed concrete. We also perform stability experiments for candidate aggregate sources.
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Historical Concrete
Concrete is not just a modernist material. On its way to the mix designs we know today, concrete has been present as oyster shell tabby in coastal regions, tamped natural cement mixes for early infrastructural works, and lightweight cinder concrete in early high-rise construction. Highbridge is uniquely qualified to assist preservation professionals in evaluating historic concrete structures.
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Infrastructure
Concrete is a highly versatile material and we expect it to perform under a variety of demanding service conditions. Effective infrastructure management requires an understanding of how well concrete resists these stresses. Engineers use our data to design effective repairs, mitigate future deterioration, and reduce overall life cycle costs.
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Parking Structures
Automobile exhaust and deicing salts tracked inside by vehicles are both agents that can accelerate steel reinforcement corrosion in parking structures. Portions of the structure may be subject to water saturation and freeze-thaw cycles particularly along ramps and exterior walls. Original precasting methods may have resulted in expansive cracking due to delayed ettringite formation. Highbridge understands these unique conditions and tailors its examinations to provide economical analytical solutions.
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New Construction
Low concrete strengths, surface defects, and cracking are common concerns that can relate to incorrect specifications, mix design deviations, or workmanship defects in new construction projects. If not resolved by an engineer’s review and nondestructive field testing, our lab scientists step in with core tests and petrography to help diagnose the cause.
Test Methods for Concrete & Aggregate
Concrete Test Methods:
ASTM C39 Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens
ASTM C42 Standard Test Method for Obtaining and Testing Drilled Cores and Sawed Beams of Concrete
ASTM C157 Standard Test Method for Length Change of Hardened Hydraulic-Cement, Mortar, and Concrete
ASTM C215 Standard Test Method for Fundamental Transverse, Longitudinal, and Torsional Frequencies of Concrete Specimens
ASTM C457 Standard Test Method for Microscopical Determination of Parameters of the Air-Void System in Hardened Concrete
ASTM C469 Standard Test Method for Static Modulus of Elasticity and Poisson's Ratio of Concrete in Compression
ASTM C496 Standard Test Method for Splitting Tensile Strength of Cylindrical Concrete Specimens
ASTM C597 Standard Test Method for Pulse Velocity Through Concrete
ASTM C642 Standard Test Method for Density, Absorption, and Voids in Hardened Concrete
ASTM C666 Standard Test Method for Resistance of Concrete to Rapid Freezing and Thawing
ASTM C856 Standard Practice for Petrographic Examination of Hardened Concrete
ASTM C1084 Standard Test Method for Portland-Cement Content of Hardened Hydraulic-Cement Concrete
ASTM C1152 Standard Test Method for Acid-Soluble Chloride in Mortar and Concrete
ASTM C1218 Standard Test Method for Water-Soluble Chloride in Mortar and Concrete
Aggregate Test Methods:
ASTM C40 Standard Test Method for Organic Impurities in Fine Aggregates for Concrete
ASTM C227 Standard Test Method for Potential Alkali Reactivity of Cement-Aggregate Combinations (Mortar-Bar Method)
ASTM C289 Standard Test Method for Potential Alkali-Silica Reactivity of Aggregates (Chemical Method)
ASTM C295 Standard Guide for Petrographic Examination of Aggregates for Concrete
ASTM C586 Standard Test Method for Potential Alkali Reactivity of Carbonate Rocks as Concrete Aggregates (Rock-Cylinder Method)
ASTM C1105 Standard Test Method for Length Change of Concrete Due to Alkali-Carbonate Rock Reaction
ASTM C1260 Standard Test Method for Potential Alkali Reactivity of Aggregates (Mortar-Bar Method)
ASTM C1293 Standard Test Method for Determination of Length Change of Concrete Due to Alkali-Silica Reaction
ASTM C1567 Standard Test Method for Determining the Potential Alkali-Silica Reactivity of Combinations of Cementitious Materials and Aggregate (Accelerated Mortar-Bar Method)