ACI Concrete Strength Technician Exam|A+
Graded
What is ASTM C1231?
Standard Practice for use of Unbonded Caps in determination of compressive strength of hardened
cylindrical concrete specimens
(C1231) The height (cavity) of the metal retaining ring must be
(25 +/- 3mm)
(C1231) If the retaining ring is greater than 4in (100mm) it must be at least __ thick. If it is less than
4in, it must be at least __ thick.
.47 in (12mm) and .35in (9mm)
(C1231) Bearing surfaces of the retaining ring must not have gauges greater than
.01 inches (.25mm) deep or .05in (32mm) surface area
(C1231) For specimen ends, depressions under a straightedge must not exceed
.2 inches (5mm) measured across any diameter using a round wire edge
(C1231) Depressions on ends of specimens that exceed ___ must be corrected by sawing or grinding
.2in (5mm)
Procedures for capping enable concrete cylinders and cores to meet C617's practice requirements
for___ and___.
perpendicularity and planeness
Capping plates can be made of what material? (C617)
glass, machined metal, polished granite, or diabase
(c1231) The inside diameter of the retaining rings shall not be less than _____% or greater than _____
% of the diameter of the cylinder.
102% and 107%
(c1231) Pad thickness must be
(13 +/- 2mm)
(C1231) The diameter of the pad shall not be more than __ smaller than the inside diameter of the
retaining ring
1/16 in (2mm)
(C1231) Neither end of the cylinder shall depart from perpendicularity by more than __ degrees
.5
(C1231) Depressions on ends of specimens that exceed .2in (5mm) must be corrected by ___ or ___
, sawing or grinding
(C1231) Tolerance on Shore A durometer hardness is +/- __
+/- 5
(C1231) The surface of the base plate that contacts the bearing block must be plane to within ___ in.
.002 in (.05mm)
Unbonded caps can be used for ASTM C__, C___, and C___
C31, C192, and C42
After application of the load, but before reaching 10% of the anticipated specimen strength, check to
see that the axis of the cylinder does not depart from vertical by more than _____ degrees.
.5 degrees
Qualification tests on an unbonded capping system must be repeated when ever there are changes in
_____ (3)
-The design or dimensions of the retaining rings
-Pad composition or thickness
-The Shore A hardness by more than 5 units
After application of the load, but before reaching _____ of the anticipated specimen strength, check
to see that the axis of the cylinder does not depart from vertical by more than .5 degrees
10%
What is ASTM C617
Standard Practice for Capping Cylindrical Concrete Specimens
What is ASTM C78
Standard test method for Flexural strength of concrete
(C78) When measuring the width and depth of the fractured face, take measurements to the nearest
___
.05in (1mm)
(C78) Can this test be conducted with a non motorized machine?
Yes, so long as it applies force at a constant rate
(C78) It is acceptable to use ___ ___ only when the gap between the specimen surface in contact with
the blocks is not more than .015in or .40 mm
leather shims
(C78) Gaps in excess of .015in or .4mm shall be eliminated only by
capping or grinding, not leather shims
Graded
What is ASTM C1231?
Standard Practice for use of Unbonded Caps in determination of compressive strength of hardened
cylindrical concrete specimens
(C1231) The height (cavity) of the metal retaining ring must be
(25 +/- 3mm)
(C1231) If the retaining ring is greater than 4in (100mm) it must be at least __ thick. If it is less than
4in, it must be at least __ thick.
.47 in (12mm) and .35in (9mm)
(C1231) Bearing surfaces of the retaining ring must not have gauges greater than
.01 inches (.25mm) deep or .05in (32mm) surface area
(C1231) For specimen ends, depressions under a straightedge must not exceed
.2 inches (5mm) measured across any diameter using a round wire edge
(C1231) Depressions on ends of specimens that exceed ___ must be corrected by sawing or grinding
.2in (5mm)
Procedures for capping enable concrete cylinders and cores to meet C617's practice requirements
for___ and___.
perpendicularity and planeness
Capping plates can be made of what material? (C617)
glass, machined metal, polished granite, or diabase
(c1231) The inside diameter of the retaining rings shall not be less than _____% or greater than _____
% of the diameter of the cylinder.
102% and 107%
(c1231) Pad thickness must be
(13 +/- 2mm)
(C1231) The diameter of the pad shall not be more than __ smaller than the inside diameter of the
retaining ring
1/16 in (2mm)
(C1231) Neither end of the cylinder shall depart from perpendicularity by more than __ degrees
.5
(C1231) Depressions on ends of specimens that exceed .2in (5mm) must be corrected by ___ or ___
, sawing or grinding
(C1231) Tolerance on Shore A durometer hardness is +/- __
+/- 5
(C1231) The surface of the base plate that contacts the bearing block must be plane to within ___ in.
.002 in (.05mm)
Unbonded caps can be used for ASTM C__, C___, and C___
C31, C192, and C42
After application of the load, but before reaching 10% of the anticipated specimen strength, check to
see that the axis of the cylinder does not depart from vertical by more than _____ degrees.
.5 degrees
Qualification tests on an unbonded capping system must be repeated when ever there are changes in
_____ (3)
-The design or dimensions of the retaining rings
-Pad composition or thickness
-The Shore A hardness by more than 5 units
After application of the load, but before reaching _____ of the anticipated specimen strength, check
to see that the axis of the cylinder does not depart from vertical by more than .5 degrees
10%
What is ASTM C617
Standard Practice for Capping Cylindrical Concrete Specimens
What is ASTM C78
Standard test method for Flexural strength of concrete
(C78) When measuring the width and depth of the fractured face, take measurements to the nearest
___
.05in (1mm)
(C78) Can this test be conducted with a non motorized machine?
Yes, so long as it applies force at a constant rate
(C78) It is acceptable to use ___ ___ only when the gap between the specimen surface in contact with
the blocks is not more than .015in or .40 mm
leather shims
(C78) Gaps in excess of .015in or .4mm shall be eliminated only by
capping or grinding, not leather shims
