ASTM C1077
ASTM C1077 is the “Standard Practice for Agencies Testing Concrete and Concrete Aggregates for Use in Construction and Criteria for Testing Agency Evaluation.” Agencies such as AASHTO provide independent accreditation […]
Testing
Prescription to performance
As part of its Prescription to Performance (P2P) initiative, the National Ready Mixed Concrete Association surveyed its members. They wanted to know which prescriptive requirements kept them from optimizing concrete. […]
Overdesign and sustainability
Acceptance of concrete delivered to the job site is usually on the basis of compressive strength tests in accordance with ASTM C31 and ASTM C39. To compensate for variability in […]
ASTM C31 and C39: the cost of bad testing
Previously we discussed acceptance testing of concrete according to ASTM C31, Standard Practice for Making and Curing Concrete Test Specimens in the Field and ASTM C39, Standard Test Method for Compressive […]
ASTM C31 and C39: what could go wrong?
For quality assurance in concrete construction, the most common acceptance criterion is the compressive strength of the concrete. A field technician makes specimens according to ASTM C31, Standard Practice for […]
Evaluating aggregates using ASTM C1778
ASTM C1778, “Standard Guide for Reducing the Risk of Deleterious Alkali-Aggregate Reaction in Concrete,” can help you decide how best to mitigate expansions due to reactive aggregates. It covers both […]
ASTM C1074 predicts the strength of concrete in place
Despite our need for durability and high performance, the most common design criterion for concrete is compressive strength. Usually we specify the 28-day strength, that is, the compressive strength after […]
Specifying tests for durable concrete
Throughout my career, our industry has been pursuing performance specifications for concrete. That is, we want specifications for what the concrete must do, not what it must be. The sticking […]
Comparing ASTM C1556 and NT Build 492
ASTM C1556 and NT Build 492 both measure the ease with which chloride ions migrate into concrete. Both test methods estimate the diffusion coefficient, a measure of the rate at […]
Preventing aggregate popouts
In Minnesota, Iowa, and South Dakota, we sometimes see aggregate popouts, particularly in concrete flatwork. Popouts are unsightly surface defects that may appear a few hours to a few weeks […]