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Strength development tests

The most important physical characteristics of fresh and hardened flowable fill mixtures are its strength development, flowability, hardening time, bleeding and shrinkage, unit weight, bearing capacity, shear strength, and corrosion resistance. Table 4.22 lists the standard test methods usually used to evaluate flowable fill materials. [Pg.188]

Structural adhesives usually require curing by the application of heat, the addition of a catalyst, the addition of pressure, or a combination of the three. The strength developed in the adhesive joint at various times during the curing process may be determined by lap shear tensile specimens. This test is commonly used to determine when an adhesive or sealant is fully cured or when the system reaches a handling strength so that the assembled product can be moved with moderate care. [Pg.443]

Cure Rate as Measured by Strength Development of Prototype Joints. Cure rate is an important factor when the expense of jigs and fixturing equipment is high or fast production rates are critical. It is also used as a quality control test to determine if the curing mechanism within the adhesive has changed from lot to lot or if it may have been spoiled by storage, moisture contamination, etc. [Pg.444]

ASTM D 1144 provides a recommended practice for determining the rate of bond strength development for either tensile or lap shear specimens. However, peel and can-teliever tests can also be used effectively. Measured bond strength values of partially cured test specimens are compared with those of a reference (i.e., fully cured adhesive joint) to assess the extent of cure. This method may suit some applications, but it is limited in accuracy because it does not directly measure the degree of cure in the adhesive, and the effect on the joint design and substrates may override the effect of cure development. [Pg.444]

At the time the end-joint test unit was being built, the industry used both horizontal and vertical end-joint profiles. This question/dilemma was eliminated by designing the unit for a lumber cross-section of 1.5 x 1.5 inches. Restriction to this dimension was also necessary to keep the power requirements within reasonable limits. At present, the unit is limited to approximately 3,000 psi in tension, at which point the hydraulically-driven grips begin to slip. The unit thus allows one to determine the strength development in the joint during the... [Pg.206]

When the components A and B were applied separately to the mating surfaces of the end-joint profiles, the tensile strength of the joints increased at very similar rates, advancing to a level of about 3,000 psi in 20 to 30 minutes at ambient temperature in both resin systems (Figure 2). Because of the negligible difference in tensile strength development and the comparatively low cost of the PRF resin, the Borden LT-75 resin was used in the component B in all further testing. [Pg.209]

Throughout the guide the term setting has been used to indicate the point at which hydration takes effect and early strength develops. It must not be confused with setting times in cement standards which are based on particular quality control test methods. [Pg.5]

Information on specific production methods can be found in the literature [Pinna 1998]. Impregnated catalysts are mainly produced batchwise with discontinuous process steps. Therefore, continuous quality control of the individual catalyst batches is vital (e.g., testing of mechanical strength, performance tests in screening reactors). The process developer must pay special attention to transferring the laboratory recipe to industrial catalyst production. Test production should be carried out relatively early... [Pg.26]

In the United Kingdom the Ministry of Defence (MOD) has issued specifications DTD 5628-5633, which cover test procedures and performance requirements for a range of products. Five strength bands and four viscosities, from penetrating to thixotropic, are defined. The torque strengths are tested on M8 nuts and bolts and the shear strength in 12-mm pins and collars. The development of these specifications and the test procedures have been described by C. L. Brett at the MOD. The breakloose torque on nuts and bolts requires particular attention to a transient measurement where the first torsional motion is detected. Other products show somewhat different behavior, with no distinct breakloose, and the torque at which the sealant begins to yield is not easily detected [77]. British Standard BS 5292 relates to the use of anaerobic sealants on gas appliances. [Pg.757]

Automatic Bonding Evaluation System (ABES) The ABES consists of a small press and a tiny testing machine in a single unit. It enables bonds to be formed under highly controlled conditions the joints that contain the bonds which are to be measured are pressed against heated blocks for a certain time, cooled within a few seconds, and pulled immediately thereafter in shear mode. Repetition of this procedure at different curing times and temperatures yields the points (a point for each specimen) of a near-isothermal strength development curve. 96,97... [Pg.918]

Psychomotor development tests Oseretsky Motor Development Scale, Bender Gestalt test, pinboard, tapping, threading beads, making dots, simple reaction time, choice reaction time, and muscular strength test. [Pg.275]

Under three point bend loading of a composite (beam), cracks may be developed due to tensile stresses at the lower stratus of the specimen as well as compression stresses at the upper one, or due to interlaminar shear. The type of failure depends on the ratio of span to depth (L/D). Short beam specimens usually fail in shear and long ones by tensile or compression stresses. For interlaminar shear strength (ILSS) tests, a L/D = 5 was chosen (ASTM-D-2344-76). In case of flexural strength tests, this ratio was fixed to 40 (DIN 29971). [Pg.305]

In 1964, Skempton observed that when clay is strained, it develops an increasing resistance (strength), but that under a given effective pressure, the resistance offered is limited, the maximum value corresponding to the peak strength. If testing is continued beyond the peak... [Pg.223]

The proper design of a profile modification treatment requires measurement of the permeability reduction caused by a given gel system. Core tests have shown that relative gel strength measurements with the capillary viscometer correlate with permeability reduction--Increasing gel strength develops higher residual resistance factors. [Pg.324]

Determination of pore pressures in sandcastles is a test of fundamental soil mechanics. The analyses require construction of Mohr circles of total and effective stress to show how negative pore pressure, coupled with friction, develops unconfined compressive strength. The tests and their analyses also illustrate relationships between water content, suction and grading. [Pg.5]

Mortars (sand and cement mixed in a proportion of 3 1) were used to develop tests to evaluate the compressive and flexural strength of the cements formed with red gypsum. These... [Pg.82]


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See also in sourсe #XX -- [ Pg.285 ]




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