B. INGGRIS - MAIN IDEA
Transcript of B. INGGRIS - MAIN IDEA
-
8/2/2019 B. INGGRIS - MAIN IDEA
1/2
LESSON 8
THE PROPERTIES OF CONCRETE : SPECIMENS FOR TESTING
-Paragraf 1 :
The standard cylinder, 300 mm high by 150 mm in diameter, is the basic specimen
used for testing concrete in Australia.
LESSON 9
THE PROPERTIES OF CONCRETE : CONCRETE COMPRESSIVE STRENGTH
-Paragraf 1 :
The compressive strength of a standard concrete cylinder, prepared and cured for
28 day in accordance with AS 1020, is used as the prime means of determining the quality
of a given batch of concrete.
-Paragraf 2 :
The inevitable variability of test results means that statistical methods must be
applied in order to obtain a measure of the concrete strength for design purposes.
LESSON 10
THE PROPERTIES OF CONCRETE : TENSILE TEST FOR CONRETE
- Paragraf 1 :For certain aspects of design it is necessary to obtain the measure of the tensile
strength of concrete.
-Paragraf 2 :
The modulus of rupture test is carried out on a standard small beam of cross-section
150 x 150 mm and length 700 mm, which is supported over a span of 600 mm (Fig. 1.5a).
-Paragraf 3 :
The cylinder-splitting test is so-called because a concrentrated line load is applied
to the sylindrical specimen laid on edge, producing a tensile stress across the vertical
diameter of the specimen (Fig. 1.5b).
LESSON 11
-
8/2/2019 B. INGGRIS - MAIN IDEA
2/2
THE PROPERTIES OF CONCRETE : SHEAR, ELASTICITY, AND CONCRETE
DENSITY
11. 1 Pure shear strength
Pure shear strength is encountered only when beding is not present of is very small.
Such as in keyways and on boding planes between surfaces.
11. 2 Modulus of elasticity (Ec)
Strictly speaking, concrete does not have an elastic modulus; this is because, as
for any elastoplastic materials, stress is not proportional to strain over a large part of the
stress range obtained in tests.
11. 4 Poissons ratio (v)
Poissons is the ratio of transverse to longitudinal strain, under axial load or stress,
within the elastic range.
11. 5 Modular ratio (n)
The modular ratio, designated by n, is the ratio of the elastic modulus for steel to
the modulus adopted for a particular grade of concrete.
11. 6 Concrete density
Concrete density, utilizing normal weight aggregates, varies from 2300 to 2500
kg/m3 when reinforced, and an average figure of 2400 kg/m3 is often adopted.
LESSON 12
TIME-DEPENDENT CHANGES IN CONCRETE VOLUME : SHRINKAGE
Shirinkage occurs of the concrete is allowed to dry in the atmosphere.
LESSON 13
TIME-DEPENDENT CHANGES IN CONCRETE VOLUME : CREEP
-Paragraf 1 :
Creep is the term applied to a reduction in concrete volume due to the application ef
external forces over a period of time, and may be present in a structure for a considerable
time (3 - 6 year).