Compressive strength testing

The hot mixes are designed by using a standard laboratory compaction procedure to develop a composition reflecting estabUshed criteria for volume percent air voids, total volume percent voids between aggregate particles, flow and stabdity, or compressive strength. Tests such as the Marshall, Unconfined Compression, Hubbard-Field, Triaxial Procedure, or the Hveem stabdometer method are used (109). 

Williams, P. D. Smith, D. C. (1971). Measurement of the tensile strength of dental restorative materials by use of a diametral compressive strength test. Journal of Dental Research, 50, 436-42. 

The diametral compressive strength has been used to estimate the tensile strength of certain AB cements (Smith, 1968). In this test, the load is applied diametrically across a cylinder of cement. Theoretical consideration of the test geometry shows that for a perfectly brittle material the failure that occurs is tensile in character. The difficulty in applying this test to AB cements is that they are not sufficiently brittle for this to hold true. In particular, the zinc polycarboxylate and glass-ionomer cements show sufficient plastic character to make the relationship between diametral compressive and tensile strength vary between AB cements of different types like the compressive strength test, this test is valid only as a means of comparison between similar materials (Darvell, 1990). 

Compressive strength Tests conducted on cores extracted from test panels shot during routine quality control show that silica fume shotcrete produce consistently higher compressive strengths and lower permeability in the hardened shotcrete than shotcrete where accelerators were used. 

As has been noted already, compression strength tests are widely used because of their speed and simplicity. Therefore, the relationship between this compressive strength most often used in practice and the theoretical tensile strength discussed in Section 2 will now be considered. 

Compressive Strength Test for Concrete Masonry Units... 

For the compressive strength test two concrete masonry units (CMUs) were cast for each plastic combination. The CMUs were Grade N according to ASTM C 90-85. The mixing procedure used to cast the CMUs at an industrial block plant in San Antonio was different from the procedure normally used at the plant Cement, sand, plastic and... 

Fig. 3.8 Diagram of force against time curves that may be obtained during the compression strength test of spherical agglomerates...

The results of relative dynamic modulus and compressive strength tests after 1000 ffeeze-thaw cycles indicate that RPC is more sound than HSM and RC. under the environmental conditions used in this study. 

The mechanical properties of concrete evaluated were the compressive and tensile strengths, at 7 and 28 days. Each result represents an average of 3 specimens. The compressive strength tests where performed according to the NP EN 12390-3 [16], where as the tensile strength test adopted was the Brazilian method, according to NBR 7222 [17], which determines the tensile strength by diametrical compression of specimens. 

In the case of the additive stabilisation process, the percentage of the hydraulic binder to be added as well as the amount of water should always be determined in the laboratory by executing CBR, M, (resilient modulus) or unconfined compressive strength tests, whichever is appropriate. 

Three adhesive formulations were chosen to cover the anticipated temperature range at the time of application, i.e. 4 C-38 °C. Control of correct mixing and materials was achieved by measuring hardness of small specimens after curing for 20 minutes in a small oven. Subsequently slant shear and compressive strength tests were performed. 

Hardened concrete properties were determined from six 150-mm x 150-mm x 150-mm cubes. After 24 h, concretes were removed from the mold and cured in lime-saturated water until the age of tests. Compressive strength tests and splitting tensile strength test were performed to determine hardened concrete properties. The results of these tests are given in Table 6. 

The compressive strength tests were performed on the hardened concrete specimens at ages of... 

Presence of rubber also makes concrete more ductile or giving . Figure 11.2 shows the force-time response (displacement control) for two compressive strength tests in which... 

Compression and compressive strength tests according to specifications ASTM D695-02a [7] and DIN EN ISO 179-1 [8]. 

Compressive Strength. The maximum load per unit area, applied at a specified rate, that a material will stand before it fails. BS 3921 specifies a compressive strength test for building bricks, specifying a strength of 5 N/mm for all... 

In order to investigate all possible combinations of PG, BPD and BOS mixtures, the combination of PG-BPD was also considered. The results for compressive strength testing are shown in Table 25. 

The effects of water content and compaction on two selected mixtures of materials were then investigated. Mixes were made using various water-to-binder ratios, and compacted using a metal tamper to achieve the maximum possible compaction. Results of compressive Strength testing are presented in Table 27. 

In order to compare the effect of hydrated and MKD waste lime in mixtures containing PG using the optimum proportions of PG-BOS-BPD and PG-BOS-ROSA-BPD obtained previously, the BPD content was replaced by commercial hydrated lime and MKD. In addition, two ternaiy mixes incoiporating ROSA, PG and lime/MKD were made to investigate the effect of lime on the activation of ROSA in presence of PG. Table 31 presents the results of compressive strength testing of these mixes. 

Due to the use of slow-reacting cementitious novel binder materials in this project, the binder content was kept at a normal amount of 380 kg/m. Compaction for 150-mm cube moulds was carried out using a hammer drill and attached plate. The results of compressive strength testing of the various concrete mixes are presented in Table 34 (all results have been converted to the strength for 150-mm standard cubes). 

To evaluate the level of compaction of concrete in the site trial and compare it with laboratory experiments, 150-mm cubes samples were prepared fiom each batch of concrete delivered to the site. Concrete samples were compacted using a hammer drill and attached plate in three layers (Figure 97). These samples were kept under standard curing conditions in the laboratory the results of compressive strength testing are presented in section 3.4. 

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