Deicing salts are often applied to the surface of pavements and bridge decks in the winter to melt ice, thereby improving safety for the traveling public. In this paper, the influence of NaCl deicing salt on freezing and thawing temperatures of pore solution and corresponding damage of mortar specimens were investigated. A low-temperature longitudinal guarded comparative calorimeter (LGCC) was developed to cool down a mortar sample at a rate of 2°C/h and to re-heat the mortar at a rate of 4°C/h. Heat flux during freezing and thawing cycles was monitored, and the temperatures at which freezing and thawing events occurred were detected. During cooling and heating, acoustic emission (AE) activity was measured to quantify the damage (cracking) caused by aggregate/paste thermal mismatch and/or phase changes. The results show that NaCl solution in a mortar sample freezes at a lower temperature than the value expected from its bulk phase diagram because of under-cooling. Conversely, the frozen solution in mortar melts at the same melting temperature as the bulk frozen NaCl solution. As the salt concentration increases, the freezing temperature is lowered. For samples containing more highly concentrated solutions, an additional exothermic event is observed whose corresponding temperature is greater than the aqueous NaCl liquidus line in the phase diagram. Damage also begins to occur at this temperature. For mortar samples saturated by solutions with 5 % and 15 % NaCl by mass, greater freeze/thaw damage is observed. The AE calorimeter developed herein is applicable for investigating damage behavior during freezing and thawing of different phases in pore solution (in mortars).

SUMMARYThe utilization of a slug calorimeter to evaluate the thermal performance of fire resistive materials (FRMs) is presented. The basic specimen configuration consists of a 'sandwich', with a square central stainless-steel plate (slug) surrounded on two sides by the FRM. This sandwich configuration provides an adiabatic boundary condition at the central axis of the slug plate that greatly simplifies the analysis. The other four (thin) sides of the steel plate (and FRM specimens) are insulated using a low thermal conductivity fumedsilica board. Two metal plates manufactured from a high temperature alloy provide a frame for placing the entire sandwich specimen slightly in compression. The entire configuration is centrally placed at the bottom of an electrically heated box furnace and the temperatures of the metal slug and exterior FRM surfaces are monitored during multiple heating and cooling cycles. Knowing the heat capacities and densities of the steel slug and the FRM, an effective thermal conductivity for the FRM can be estimated. The effective thermal conductivity of the FRM will be influenced by its true thermal conductivity and by any endothermic or exothermic reactions or phase changes occurring within the FRM. Preliminary tests have been conducted on two commonly used FRMs and on a non-reactive fumed-silica board to demonstrate the feasibility of the method. Published in 2005 by John Wiley & Sons, Ltd.

New da ta a re ~rese nt e d for th e th erm a l condu c tivit y a nd e lec tri cal res is tivit y of tw o s amp lc s of Armco iru n. O n a sa mp!~ of ma te rial use d in a ruund ro bin co mpari so n be tw ee n seve ral laboratories , th c rmal condu c tivit y wa· s meas ured from -160 to + 640 °C and e lec tri cal res istivit y was meas ured from -195 tu + 1380 °C. On a s ampl e of co ld ·work e d A rm co irun frum a diffe re nt lot , dat a are re port ed fro m -150 to + 200°C.Key Word s: Ar m (;o iron , condu c tivit y. e lectri cal co ndu c ti vit y. elec tri ca l res ist ivity. hea t co n· ductivity , hea t tran s fe r. iron. Lore n z fun c ti o n, res is ti vit y. th e rmal co ndu c ti vit y.

Laboratory tests of sound transmission loss, thermal transmittance , and rate of air leakage were conducted on full scale (9 feet high x ik feet wide; 2.7 x 1+.3 meters) specimens of typical residential exterior wall constructions, either unbroken or penetrated by a door or window. The walls were of wood frame construction with gypsum board dfywall interior finish and exterior finishes of wood siding, stucco, or brick veneer. Additional acoustical tests were run on a number of individual doors and windows. A total of 109 acoustical tests and kQ thermal tests are reported. The resultant data are compared with literature data on similar constructions. Correlations developed among the several quantities measured will assist more rational design where both energy conservation and noise isolation must be considered.

No abstract