Water curing

J. B. Egraz, H. Grondin, and J. M. Suau. Acrylic copolymer partially or fully soluble in water, cured or not and its use (copolymere acrylique partiellement ou totalement hydrosoluble, reticule ou non et son utilisation). Patent EP 577526, 1994. 

Depending on the extent of expansion achieved in the wet curing period and the rate of shrinkage soon after water curing ceases, significant contraction can occur (Fig. 6.13). 

The Romans pioneered the use of hydraulic, or water-cured, cement. Its unique chemical and physical properties produced a material so lasting that it stands today in magnificent stmctures like the Pantheon. Yet the formula was forgotten in the first few centuries after the fall of the Roman Empire and wasn t rediscovered until 1824 as Portland cement. One Roman version was based on a burned mixture of two major components volcanic ash—called pozzolana—from Mount Vesuvius, which destroyed Pompeii and nearby towns in... 

Availability of extra blind flanges for hot water curing... 

Autoclave curing Open steam curing Hot water curing Self-vulcanizing Cold bond lining and... 

Hot water cures can be used for articles that are not affected by immersion in hot water. This method is useful for thick walled articles and rubber lined equipment and especially most suitable for ebonite compositions. Direct contact with water produces better heat transfer than with hot air or steam. Consequently this system gives less deformation of products during cure. 

Hot water cure - A method for curing rubber in hot or boiling water. Colloquial. 

In order to minimize surface preparation, concrete surfaces are usually water cured for 28 days however, the use of curing agents cannot be altogether avoided so special care must be taken to assure the selected agent is compatible with the coating used. 

Autoclave-cured specimens including FRP powder do not show superiority in flexural strength while water-cured specimens including 9.1% of FRP powder indicate excellent strength. 

Keywords asbestos-free mortar, autoclave curing, extrude, flexural strength, FRP powder, porosity, water curing... 

In case of autoclave curing, the specimens were cured in the condition of 150 degree Cels, steam for 8 hours. For getting this condition, it took 5 hours for ascending temperature and 12 hours for cooling. In case of water curing, the specimens were cured in water of 20 degree Cels, for 28 days. 

Before bending tests, all specimens were ground to make the surfaces smooth and to have the same thickness. All specimens were dried at 105 degree Cels, for 48 hours. Water absorption ratio was measured by the difference of weight before and after drying only in the case water curing. 

Intrusion volume of all autoclave-cured composites was bigger than that of water-cured except PAO. It is noticeable that the pore diameters of autoclaved composites exceed in diameters of 1 micrometer and 0.01 micrometer while water-cured ones exceed in 0.1 micrometer. Among all cases, water-cured PA1 shows the minimum intrusion volume, which performed the maximum flexural strength. 

Average pore diameter of all composites that contain FRP powder increased in accordance with the FRP content. The ratio of pore surface of autoclave-cured specimens to water-cured ones decreased in accordance with FRP content ratio, which may indicate emergence of coarse hydration products or generation of bigger pores in case of autoclave-curing. (See Table 7)... 

Note AC150 means autoclave-cured. W28 means water-cured for 28 days. 

Typical SEM photographs of fractured surface after bending tests are shown in Fig. 8 and Fig. 9. Shown in Fig. 8 is the surface of autoclave-cured PA3 composite. Fig. 9 shows the surface of water-cured PA3 composite. In the case of water-cured composites, there remained many sound GF compared with autoclave-cured composites that mostly contain degraded GF-like vague materials. 

The BD of autoclave-cured and water-cured composites is mostly equal and showed the same decreasing feature in accordance with FRP content. 

On the other hand, the order of strength in the case of water-cured specimens differs from that of autoclave-cured specimens. PA1 shows highest flexural strength. The increase of FRP content means decrease of flexural strength in this case, too. However, PA and PAO that contain no FRP powder indicate lower strength. 

Flexural strength of all water-cured specimens showed lower strength than that of autoclave-cuned ones except PA1. This exception may be caused by the reinforcing effect of GF, only when the content of FRP powder is... 

FRP powder inevitably contains GF. The curing condition that does not degrade GF can bring high strength as observed water-cured PA1, though durability problem should be considered. 

If specimens are cured in the autoclave, the strength of composites including FRP powder drastically dropped to the level of water-cured specimens. 

Use Dyes, sensitive reagent for gold (1 10 million detectable) and for free chlorine in water, curing agent for urethane resins (also available as the dihydrochloride). 

The REX process is normally carried out in two steps, with the first step occurring at 180-200 "C. The mixture is passed through another REX reactor for mixing, and then through a final shaping REX reactor to complete the water curing reaction. The final cross-linked product (Sioplas ) is used as a wire or cable coating. 

Prior to casting, the mixed formulations were filtered for removal of particulate and insoluable matter and transferred to special canisters. Casting was done at ambient temperatures and water curing at 1°C for a period of 45 minutes. Prior to use, the membranes were first annealed and then slit into strips, say... 

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