Purpose of Field Testing of Concrete

Field Testing of Concrete

Concrete testing in the field is necessary in some situations to serve various purposes.

Concrete testing may be divided into three fundamental types.

Quality Control testing

This is normally performed by the contractor or concrete producer to determine if there are necessary adjustments to make sure the concrete is acceptable.

Compliance testing

This category is performed by engineers according to the specs to judge the compliance with the specifications.

Secondary testing

This kind of testing is conducted on hardened concrete in times where there are questions regarding the reliability of control and compliance results. Also, if the results of the control and compliance tests are not satisfactory, not available (e.g. in old and/or damaged concrete), or inappropriate. All testing which is not planned before construction will be in this category

Purpose of Field Testing of Concrete

They have the benefit of detecting faults including insufficient cover, excessive surface permeability, voids, honeycombing, or the use of inappropriate materials that could otherwise go undetected yet result in long-term durability issues. Another significant and expanding application is testing the integrity of repairs. In-situ testing is mostly used as secondary testing, which may be required for a variety of reasons. There are basically two types of them.

Adherence to the specification

The most typical example is when more proof is needed in contractual disputes if standard specimens did not follow the specs. Other situations entail looking back after the structure has deteriorated, which is usually connected to assigning guilt in legal actions. Most specifications place a high priority on strength requirements, thus the engineer must choose the most appropriate techniques for evaluating in-situ strength on a representative basis while fully aware of the potential variances to be anticipated within different structural elements. A significant challenge occurs when connecting observed in-situ strength to expected equivalent “standard” specimen strength at a specified but different age. The data should be analysed to identify in-situ variability as well as strength. Borderline cases may thus be difficult to prove conclusively.

In order to fulfil the criteria for durability, a minimum cement content will often be established, and compliance may need to be verified using chemical or petrographic testing. Similar tests could also be necessary to check for the presence of prohibited additives, contamination of concrete ingredients (such as chlorides in sea-dredged aggregates), or entrained air, as well as to confirm cement content after degradation. The main source of durability issues is frequently poor craftsmanship, although testing may also be used to show insufficient cover or compaction, inappropriate reinforcing amounts or locations, or inadequate curing or specialized procedures like grouting of post-tensioned construction.

Evaluation of in-situ integrity and quality

The performance of the existing structure in the present and the future are the main issues here. In-situ testing is being used in routine maintenance of concrete buildings to help with “lifetime forecasts”. It’s critical to make a distinction between the necessity to evaluate a material’s characteristics and the overall performance of a structural member.

Testing may be necessary for a number of reasons, like as

• Proposed modification (such as change in function) or enlargement of a structure
• A building’s suitability for purchase or insurance
• After material degradation or structural damage from a fire, explosion, fatigue, or overload, an assessment of structural integrity or safety is performed.
• Serviceability or capacity of members with knowledge or fear that they include materials that don’t meet requirements or that have flaws in their design
• Prior to designing repair or remedial plans, the cause and amount of degradation are assessed.
• Evaluation of the effectiveness or integrity of the applied repairs
• monitoring the strength development in connection to the application of loads or the prestressing, curing, or stripping of formwork
• Observing long-term changes in the structural performance and material qualities.

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