Freeze-thaw environment

The following review concerns both saturated and dry fiber RP samples that will be placed in an accelerated freeze-thaw environment and... 

Gradient across component thickness No. of cycles—high to low No. of cycles—freeze-thaw Solar gain, surface air flow Liquid, moisture, and/or vapor tightness Strength-weight ratios—relative significance Service environment ... 

In addition to being potentially less costly to construct, ET covers have the potential to provide equal or superior performance compared to conventional cover systems, especially in arid and semiarid environments. In these environments, they may be less prone to deterioration from desiccation, cracking, and freezing/thawing cycles. ET covers also may be able to minimize side slope instability, because they do not contain geomembrane layers, which can cause slippage.5-42 43... 

The resistance to freeze-thaw cycling which may be experienced during the winter months in many countries. This will not be a function of the average wintertime temperatures of the various countries because, in fact, the very cold environments will have only a small number of freeze-thaw cycles. In countries such as Great Britain, the winter daytime temperatures are often above 0°C and the night-time temperature below. In view of this, more freeze-thaw cycles would be experienced than in countries such as Scandinavia or North America where daytime temperatures in the winter tend to remain below 0°C. 

Mitchell, North Carolina, Air Waste, 43, 1074-1083 (1993). Arakaki, T., C. Anastasio, P. G. Shu, and B. C. Faust, Aqueous-Phase Photoproduction of Hydrogen Peroxide in Authentic Cloud Waters Wavelength Dependence, and the Effects of Filtration and Freeze-Thaw Cycles, Atmos. Environ., 29, 1697-1703 (1995). Arakaki, T., and B. C. Faust, Sources, Sinks, and Mechanisms of Hydroxyl Radical ( OH) Photoproduction and Consumption in Authentic Acidic Continental Cloud Waters from Whiteface Mountain, New York The Role of the Fe(r) (r = II, III) Photochemical Cycle, . /. Geophys. Res., 103, 3487-3504 (1998). Atkinson, R., D. L. Baulch, R. A. Cox, R. F. Hampson, Jr., J. A. Kerr, M. J. Rossi, and J. Troe, Evaluated Kinetic and Photochemical... 

Differences in performance are also noted depending on the specific nature of the environment. Differences can be expected in joint durability when bonds are exposed to an aggressive wet-freeze-thaw cycle, marine seacoast, or inland environments. Outdoor weathering conditions are often classified by one of the following exposure conditions ... 

Freeze-thaw cycles also create an environment of slow cooling which enhances crystallization from DMSO. The amorphous material, that initially dissolved in DMSO, can crystallize at low temperature in the refrigerator and become more difficult to re-dissolve. This is because the high-energy amorphous... 

ABSTRACT This research project aims to use reactive powder concrete, RPC. as a new repair material and evaluate its bond strength and bond durability to existing concrete. One accelerated aging environment, namely a freeze-thaw cycle acceleration deterioration test, was selected for the evaluation of bond durability of the repair materials. Before and after aging, the samples were evaluated by the compressive strength, bond strength (slant shear test), steel pull out strength, and relative dynamic modulus NDT tests. 

In the modem age, a highly developed infrastructure is essential for economic growth and prosperity. Many stmctures essential to this infrastmcture, especially those made of reinforced concrete, have suffered severe degradation since their construction due to the combined effects of deicing salts, freeze-thaw cycles, aggressive environments, and drastically increased live loads. One of the major problems facing the civil engineers of today is to preserve, maintain, and retrofit these structures [1],... 

As many excipients are capable of stabilizing proteins under different conditions, it is unlikely that the stabilization effect is excipient-specific. It is widely believed that the stabilizing mechanism of excipients involves the preferential exclusion of the added excipient from the protein in aqueous solution and during freeze-thawing [192]. Briefly, a protein in an aqueous environment is in dynamic equilibrium between the native and the denatured (unfolded) forms. As the exclusion of excipient from the unfolded form is greater than that from the native form, the equilibrium will shift toward increasing concentration of the native form. Thus, the unfolding of protein in the presence of excipient is a thermodynamically... 

Other special requirements for specific environments are, for example, a minimum content of entrained air in concrete exposed to freeze-thaw attack or specific types of cement for concrete exposed to sulfate attack (see Chapter 3). 

The repair material should also be able to resist other types of attack that could occur in the specific environment (sulfate, freeze-thaw, etc.). 

---