CONCRETE TEST ACTUAL EXAM PAPER
2026 QUESTIONS WITH ANSWERS
GRADED A+
◍ ITZ interfacial transition zone.
Answer: area around large particles (aggregate) in concrete matrix that is
weaker due to higher w/c ratio-die to preferential alignment of hydration
products around the large particles
◍ When rodding the middle and the top layers, the tamping rod should
penetrate into the layer below approximately _____..
Answer: 1 in. [25 mm]
◍ type 3 failure.
Answer: columnar vertical cracking through both ends, no well-formed ends
◍ When the concrete contains aggregate larger than allowed for the slump test,
the large aggregate must be _____..
Answer: Removed by wet sieving the sample over 1.5 in. [37.5 mm] sieve
◍ What is the required minimum frequency of the vibrator used in this test
method?.
Answer: 7000 vibrations per minute
◍ The maximum size aggregate allowed for this test method is _____..
Answer: 50 mm (2 in.)
◍ The temperature measuring device shall be calibrated _____, or whenever
there is a question of _____..
Answer: Annually, accuracy
◍ comp strength testing: as distance from plates increases, the stress in x and
y.
, Answer: decreases-the compressive stresses in the radial (x, y) directions act
as confinement, increasing the strength
◍ What is the specified size of the mallet required for this test method when
the measuring bowl has the capacity of 14 L [0.5 ft^3] or less?.
Answer: 0.60 +- 0.25 kg [1.25 +- 0.50 lb.]
◍ E, stiffness modulus increases as w/c.
Answer: increases
◍ Concrete mixtures with specified strengths of 6000 psi [40 MPa] or greater
shall have an initial curing temperature between __________..
Answer: 68 and 78 degrees F [20 and 26 C]
◍ compressive strength testing: poissons ratio,solution:.
Answer: aspect ratio-height/diameter = 2
◍ In rodding the sample, how deep should the rod penetrate each layer?.
Answer: Rod bottom layer to full depth; rod second and final layer
penetrating the previous layer about 25 mm (1 in.)
◍ type 5.
Answer: side fractures at top or bottom (occur commonly w unbonded caps)
◍ can determine tensile strength in lab by.
Answer: indirect methods
◍ If vibration is the method of consolidation, the measure must be filled in
_____ approximately equal layers..
Answer: 2
◍ flexural beam testing.
Answer: modulus of rupture, fᵣ -represents the tensile strength of concrete in
bending-used to assess cracking and deflection
◍ What type of alcohol and concentration must be used in this test method?.
Answer: Isopropyl, 70% by volume (65% by weight)
◍ The volumetric method of determining air content of concrete can be used
, on concrete containing what types of aggregate?.
Answer: All types of aggregate
◍ What must be done to the sample container prior to sampling the concrete?.
Answer: Dampen (with water)
◍ How deep should the tamping rod penetrate into each layer?.
Answer: Rod each layer throughout its depth; on the second and final layers,
the rod should penetrate into the previous layer approximately 1 in. [25 mm]
◍ compressive strength testing: non-flat or rough service,solution:.
Answer: end caps-sulfur or neoprene
◍ type 2 failure.
Answer: well formed cone on one end, vertical cracks running through caps,
no well defined cone on either end
◍ A mallet weighing ____ must be used to tap the sides of the bowl after
rodding each layer..
Answer: 1.25 +- 0.50 lb. (600 +- 200 g)
◍ Up to 48 hours after molding, test specimens that are to be standard cured
shall be stored in a temperature range between _____ to _____..
Answer: 60 and 70 degrees F [16 and 27 C]
◍ The sample of concrete used in this test method must be obtained in
accordance with what ASTM Standard?.
Answer: C172
◍ type 6 failure.
Answer: similar to type 5 but end of cylinder is pointed
◍ Measures other than air meter bowls used for this test must conform to
ASTM _____..
Answer: C29
◍ type 1 failure.
Answer: reasonably well-formed cones on both ends, less than 1" of
cracking through caps
2026 QUESTIONS WITH ANSWERS
GRADED A+
◍ ITZ interfacial transition zone.
Answer: area around large particles (aggregate) in concrete matrix that is
weaker due to higher w/c ratio-die to preferential alignment of hydration
products around the large particles
◍ When rodding the middle and the top layers, the tamping rod should
penetrate into the layer below approximately _____..
Answer: 1 in. [25 mm]
◍ type 3 failure.
Answer: columnar vertical cracking through both ends, no well-formed ends
◍ When the concrete contains aggregate larger than allowed for the slump test,
the large aggregate must be _____..
Answer: Removed by wet sieving the sample over 1.5 in. [37.5 mm] sieve
◍ What is the required minimum frequency of the vibrator used in this test
method?.
Answer: 7000 vibrations per minute
◍ The maximum size aggregate allowed for this test method is _____..
Answer: 50 mm (2 in.)
◍ The temperature measuring device shall be calibrated _____, or whenever
there is a question of _____..
Answer: Annually, accuracy
◍ comp strength testing: as distance from plates increases, the stress in x and
y.
, Answer: decreases-the compressive stresses in the radial (x, y) directions act
as confinement, increasing the strength
◍ What is the specified size of the mallet required for this test method when
the measuring bowl has the capacity of 14 L [0.5 ft^3] or less?.
Answer: 0.60 +- 0.25 kg [1.25 +- 0.50 lb.]
◍ E, stiffness modulus increases as w/c.
Answer: increases
◍ Concrete mixtures with specified strengths of 6000 psi [40 MPa] or greater
shall have an initial curing temperature between __________..
Answer: 68 and 78 degrees F [20 and 26 C]
◍ compressive strength testing: poissons ratio,solution:.
Answer: aspect ratio-height/diameter = 2
◍ In rodding the sample, how deep should the rod penetrate each layer?.
Answer: Rod bottom layer to full depth; rod second and final layer
penetrating the previous layer about 25 mm (1 in.)
◍ type 5.
Answer: side fractures at top or bottom (occur commonly w unbonded caps)
◍ can determine tensile strength in lab by.
Answer: indirect methods
◍ If vibration is the method of consolidation, the measure must be filled in
_____ approximately equal layers..
Answer: 2
◍ flexural beam testing.
Answer: modulus of rupture, fᵣ -represents the tensile strength of concrete in
bending-used to assess cracking and deflection
◍ What type of alcohol and concentration must be used in this test method?.
Answer: Isopropyl, 70% by volume (65% by weight)
◍ The volumetric method of determining air content of concrete can be used
, on concrete containing what types of aggregate?.
Answer: All types of aggregate
◍ What must be done to the sample container prior to sampling the concrete?.
Answer: Dampen (with water)
◍ How deep should the tamping rod penetrate into each layer?.
Answer: Rod each layer throughout its depth; on the second and final layers,
the rod should penetrate into the previous layer approximately 1 in. [25 mm]
◍ compressive strength testing: non-flat or rough service,solution:.
Answer: end caps-sulfur or neoprene
◍ type 2 failure.
Answer: well formed cone on one end, vertical cracks running through caps,
no well defined cone on either end
◍ A mallet weighing ____ must be used to tap the sides of the bowl after
rodding each layer..
Answer: 1.25 +- 0.50 lb. (600 +- 200 g)
◍ Up to 48 hours after molding, test specimens that are to be standard cured
shall be stored in a temperature range between _____ to _____..
Answer: 60 and 70 degrees F [16 and 27 C]
◍ The sample of concrete used in this test method must be obtained in
accordance with what ASTM Standard?.
Answer: C172
◍ type 6 failure.
Answer: similar to type 5 but end of cylinder is pointed
◍ Measures other than air meter bowls used for this test must conform to
ASTM _____..
Answer: C29
◍ type 1 failure.
Answer: reasonably well-formed cones on both ends, less than 1" of
cracking through caps
