Concrete Surface Cracks
Concrete Surface Cracks - Related Videos
01:28
Types of Non-structural Cracks in Concrete
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2024
Non-structural cracks are primarily of three types: plastic, early-age thermal, and drying shrinkage cracks. Plastic cracks are further classified into plastic shrinkage cracks and plastic settlement cracks. Plastic shrinkage cracks typically form within hours after the concrete is poured. The concrete's surface dries faster than the bottom, creating tensile stress that the still-plastic concrete cannot withstand, leading to diagonal or randomly patterned cracks on the concrete surface. Plastic...
10:09
Tests of Hardened Concrete in Tension
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2023
Source: Roberto Leon, Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA In a previous laboratory focused on concrete in compression, we observed that concrete can withstand very large stresses under uniaxial compressive forces. However, the failures observed were not compressive failures but failures along shear planes where maximum tensile forces occur. Thus, it is important to understand the behavior of concrete in tension and particularly its maximum strength...
11:23
Tests on Fresh Concrete
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2017
Source: Roberto Leon, Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA Concrete consists of two phases, a cement paste phase comprised of cement, water, and air, and an aggregate phase comprised of coarse and fine aggregates. There are two key considerations when designing a concrete mix. First, the concrete must be workable and easy to cast in the forms in its fresh condition, even when the forms are packed with steel reinforcement. In this condition, it is the...
08:08
Compression Tests on Hardened Concrete
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2023
Source: Roberto Leon, Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA There are two distinct stages in a construction project involving concrete. The first stage involves batching, transporting, and casting fresh concrete. At this stage, the material is viscous, and the workability and finishability are the key performance criteria. The second stage occurs when the hydration process begins shortly after the concrete is placed in the form, and the concrete will...
10:10
Aggregates for Concrete and Asphaltic Mixes
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2023
Source: Roberto Leon, Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA Concrete and asphalt are by far the most common construction materials used today. Concrete is a composite material consisting of cement, water, air, coarse aggregate, and fine aggregates. Fine aggregates are typically sands and coarse aggregates are natural or crushed rocks. Chemical admixtures to modify certain specific properties are also commonly used (i.e., superplasticizers to make the...
FAQs
Drying shrinkage creates contraction as moisture leaves hardened concrete. If that movement is restrained, tensile stress develops within the material. Once the stress exceeds concrete’s limited tensile capacity, a surface crack can form. The amount of restraint therefore affects whether shrinkage appears as harmless strain or visible damage, helping engineers connect cracking to construction conditions and durability concerns.
Crack width, depth, pattern, and timing provide complementary evidence rather than a single diagnosis. Width indicates the extent of opening, while depth shows whether damage remains near the surface. Pattern and timing help relate the observation to drying shrinkage, thermal movement, plastic settlement, or applied loads. Reviewing all four characteristics supports more defensible condition assessment and repair decisions.
Thermal movement, plastic settlement, and applied loads impose strain under different conditions. Thermal movement reflects temperature-related dimensional change, plastic settlement occurs while concrete is settling, and applied loads act on hardened material. Each can create restraint and localized strain, so engineers use when the crack appeared and its visible pattern alongside width and depth to interpret the likely cause.
A systematic inspection should document crack width, depth, pattern, and timing, then relate those observations to possible sources such as drying shrinkage, thermal movement, plastic settlement, or applied loads. Engineers can then consider whether the condition suggests leak risk, corrosion risk, or a need for continued monitoring. This record supports consistent assessment and decisions about sealing, repair, or strengthening.
Crack observations help engineers evaluate potential leak and corrosion risks during condition assessment. Width and depth are especially useful alongside pattern and timing, because the complete description gives more context than visibility alone. The resulting assessment can determine whether to seal the crack, repair the concrete, strengthen the element, or continue monitoring.
Crack findings can improve future engineering decisions beyond immediate repair. Observed patterns and likely causes inform mixture design, curing, and joint placement, while ongoing maintenance uses inspection results to identify conditions that require monitoring. This feedback links field evidence with construction practice, helping reduce recurrence and support better durability.