Concrete Testing & Evaluation Flashcards
7 cards from real CCI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Concrete Testing & Evaluation flashcards as text
A splitting tensile strength test (ASTM C496) is performed by loading a concrete cylinder:
Answer: Diametrically in compression along its length
The splitting tensile test applies compressive load along a diametral plane of the cylinder, inducing transverse tensile stresses that split the specimen.
The maturity method for estimating concrete strength is based on the relationship between strength and:
Answer: Time and temperature history of the concrete
The maturity method (ASTM C1074) uses the temperature-time history (maturity index) of curing concrete to estimate in-place strength from a pre-established strength-maturity relationship.
When performing a concrete temperature measurement per ASTM C1064, the thermometer must remain inserted in the fresh concrete sample for at least:
Answer: 2 minutes
ASTM C1064 requires the thermometer to be inserted to a minimum depth of 3 inches and left in place for at least 2 minutes before recording the temperature.
ACI 305R hot-weather concreting guidelines recommend that the maximum concrete temperature at point of discharge should not exceed:
Answer: 90°F (32°C)
ACI 305R recommends a maximum concrete temperature of 90°F (32°C) at point of discharge to prevent accelerated setting, reduced strength, and cracking.
What is the primary purpose of performing a sieve analysis on concrete aggregates during inspection?
Answer: To verify gradation conforms to specification
Sieve analysis (ASTM C136) separates aggregate particles by size to verify that the gradation meets specification requirements affecting workability, strength, and durability.
Popouts on a hardened concrete surface are typically caused by:
Answer: Expansive aggregate particles near the surface
Popouts occur when individual aggregate particles near the surface absorb moisture and expand due to freeze-thaw cycling or alkali reactivity, fracturing the surrounding paste.
When evaluating concrete for alkali-silica reaction (ASR) in an existing structure, which field indicator is most characteristic of this distress mechanism?
Answer: Map cracking with gel exudate at crack edges
ASR produces expansive silica gel within the paste that absorbs moisture and swells, creating random map cracking with a characteristic whitish gel visible at crack surfaces.