Studies of the Effect of Heat Treatment on Stress-Produced Failure in Compressed Concrete
This paper points out that the fracture process of plain concrete subjected to lowpressure steam heat treatment is different from that of the normally cured concrete. This was established by tests carried out by the methods of acoustic emission and strain measurements. The tests revealed that heat-treated concrete displays a considerably lower fatigue strength and a slightly higher long-term strength. This fact should be taken into account both in planning the cycles of heat treatment of concrete or in designing the prefabricated concrete structures, the safety of which largely depends on fatigue strength.
References
G.CHRABCZYŃSKI, Heat treatment of concrete in industrial production of prefabricated elements, [in Polish], Warsaw Techn. Univ. Sci. Reports (Civil Enging),68, 1980.
K.FLAGA, Energy principles of strength increase in concrete solidifying under heat treatment conditions, [in Polish], Cracow Techn. Univ. Sci. Reports (Civil Enging), 40, 1971.
K.FLAGA and K.FURTAK, Effect of aggregate quality on critical stress levels in compressed concrete, [in Polish], Arch. Inż. Ląd., 26, 4, pp.653-666, 1982.
K.FURTAK, Load carrying capacity of reinforced concrete cross-sections subject to variable bending; application to bridge structures, [in Polish], Cracow Techn. U niv. Sci., Reports (Civil Enging.), 64, Hab. Dissertation, 1985.
К.Е.ГОРЯНОВ, Е.С.ВЕКСЛЕР, Деструкцвя в твердеющем бетонераннего возраста ирн нагреве н способы умещния ее интенснвностм, Труды РИЛЕМ ИЛПС, 56-61, Москва 1968.
J.HOŁA and A.MOCZKO, Failure analysis of certain concrete structures by means of the ultrasonic and acoustical emission methods, [in Polish], Wrocław Techn. Univ., Ph. D.-Dissertation, 1984.
J.HOŁA, Selected problems of fracture mechanics of concrete subject to ageing treatment, [in Polish], Cement - Wapno - Gips, 10-11, pp. 230-252, 1990.
T.C.HSU, F.O.SLATE, G.M.STURMAN and G.WINTER, Microcracking of plain concrete and the shape of the stress-strain curve, ACI J., 60, 2, pp. 209-224, 1963.
A.KUŚNIERZ and K.FLAGA, Heat treatment of concrete in microwave field, [in Polish], XXXIII Sci. Conf. of the P.A.S. Civil Enging. Committee, Krynica 4, pp. 85-90, 1987.
K.NEWMAN and I.B.NEWMAN, Failure theories and design criteria for plain concrete. Structure, solid mechanics and engineering design, Proc. Southampton, 1969; Civ. Eng Mat. Conf., pp. 963-995, London 1971.
С.РЕИНСДОРФ, Пропаривание бетона при атмосферном давлении, Труды, РИЛЕМ, 130-139, Москва 1968.
J.RUPPERT, M.LIBURA and W.ZARĘBSKA, Limit states of cracking of reinforced concrete beams made of carbonate concrete, [in Polish], Inż. i Bud., 9-10, pp.326- 327, 1980.
H.RUSCH, Physikalische Fragen der Betonpriifung, Zement-Kalk-Gips, 12, 1, pp. 1-9, 1959.
S.P.SHAH and S.CHANDRA, Critical stress volume change and microcracking of concrete, ACI J ., 65, 9, pp. 770-781, 1968.
B.STAWISKI, Effect of heat treatment and aggregate size on the quality parameters of concrete in prefabricated elements tested by ultrasonic methods, [in Polish], Wrocław Techn. Univ., Ph.D.-Dissertation, 1975,
V.A.YERLICI, Behaviour of plain concrete under axial tension, ACI J., 62, 8, pp.987-991, 1965.