Field measurements to assess the long-term behavior of reinforced concrete structures are described. Results are presented of the preliminary investigations related to the strain gages being used, the gage installation techniques adopted, the methods being used to test the concrete, and the methods that will be used to estimate the stresses in the concrete. Some of the observations made to date on the building and the concrete specimens are also presented.
Loganathan, P & Burau, RG 1973, 'Sorption of heavy metal ions by a hydrous manganese oxide', Geochimica et Cosmochimica Acta, vol. 37, no. 5, pp. 1277-1293.
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Sorption of Co, Zn, Ca and Na by δ-MnO2 was studied at 24.0 ± 0.5°C and pH 4. During the sorption of Co and Zn, Mn was released to the solution phase; however, Mn release was not detected during the sorption of Ca and Na. On the basis of crystal field theory, it is proposed that Zn may interchange with Mn2+ in the δ-MnO2 structure, whereas Co may interchange with both Mn2+ and Mn3+. It is suggested that the interchangeable Mn2+ and Mn3+ sites were in the disordered layers in the δ-MnO2 structure. Sorption of Co, Zn and Ca at pH 4 fitted single-site Langmuir isotherm expressions at all Ca concentrations, but only at concentrations greater than 10-4 M for Co and Zn. Mn release by δ-MnO2 at pH 4 during Co and Zn sorption also fitted single-site Langmuir isotherms. An expression for the case of multisite Langmuir sorption was derived and applied to the cases of Co and Zn sorption and to the case of Mn release during Co sorption. The data of these cases were used to calculate statistically the coefficients of multiple regression equations from which the sum of the capacities of all sites in each case were obtained. From all of these derived capacities, it is proposed that there was only one site where Ca interchanged with surface bound H. Zn was postulated to interchange not only with these bound H sites, but also with another site where it interchanged with structural Mn2+. Co was postulated to interchange with both of these sites, and additionally, with a third site where it interchanged with structural Mn3+. Using a pH-stat set at pH 4, it was determined that approximately 2 moles of H were released per mole of Co or Zn sorbed at bound H sites. © 1973.
Winterkorn, HF, Christensen, RW, Das, B, Wischmeier, WH, Meyer, LD, Akky, MR, Shen, CK, Arulanandan, K, Sargunam, A, Loganathan, P, Krone, RB & Paaswell, RE 1973, 'SOIL EROSION: CAUSES AND MECHANISMS; PREVENTION AND CONTROL.', Highw Res Bd, Spec Rep, no. 135.
Proceedings includes 14 papers dealing with the causes and mechanisms of soil erosion and methods of preventing and controlling erosion. Following is part I of the list of titles and authors of the papers presented: Experimental Study of the Attack of Water on Dry Cohesive Soil Systems. By Hans F. Winterkorn. Hydraulic Erosion of Remolded Cohesive Soils. By Richard W. Christensen and Braja M. Das. Soil Erodability on Construction Areas. by M. R. Akky and C. K. Shen. Hydraulic Erosion of Remolded Cohesive Soils. By W. H. Wischmeier and L. D. Meyer. Erodibility of a Cement-Stabilized Sandy Soil. By M. R. Akky and C. K. Shen. Application of Chemical and Electrical Parameters to Prediction of Erodibility. by K. Arulanandan, A. Sargunam, P. Loganathan, and R. B. Krone. Causes and Mechanisms of Cohesive Soil Erosion: The State of the Art. By Robert E. Paaswell.