04567nam a2200409 4500 20260818155827.0 270798 th eng .b10454792 AIT Thesis no. ST-91-23 Sharma, Anil Movement of water in concrete incorporating air-phase Bangkok : Asian Institute of Technology, 1991 90, A-3, B-2, C-2 p. Thesis ; no. ST-91-23 A thesis submitted in partial fulfillment of t he requirement for the degree of master of engineering, School of Engineering and Technology Thesis (M.Eng.) - Asian Institute of Technology, 1991 The longevity and durability of concrete remain a continuing a rea of research activity a nd thought . The process of deterioration of concrete is mediated largely by water . I n this research the movement of water in the capi11ary pore s paces of concrete was studied indifferent conditions . In the present study key is the consideration of multi - phase or Gas-Liquid movement, liquid phase movement is associated with the gas phase. Water plays a dual role in corrosion phenomenon. It acts as the carrier medium for some elements of corrosion like Cl- in its liquid phase , o n t he other ha nd it prevents the passage of other elements like o2. For corrosion of steel lying just below t he cover concrete , the alternate wetting a nd drying cycle is very dangerous as he r e the ingress of elements of corrosion can take place . In this study the movement of water in the wet tingcycle was considered mainly in t he concrete of various mix proport ions. Here water moves as a liquid in the capillary pore spaces of concrete, driven by t he forces of surface tension, pressure gradient and is resisted by t he friction between wat e r and concrete. The effect of water/cement ratio , absorption pressure , length of specimen, curing age , initial conditions , bleeding , and gravity on the water movement was studied . In the field structures, deterioration level s are different in bridge deck like structures a nd column structures. I n this study, for a l 1 the tests two boundary conditions A a nd B we reused, simulating the field situation in above two types of structures. Boundary conditions are related to the movement of the air phase. In boundary condition A, since the top face is open so gas phase movement is free, as water comes in t he capillary pore spaces air escapes from t he top. In boundary condition B, since top face is sea led so gas phase movement is stopped. As water movement occurs , space available to air reduces a nd a pressure 4 Pa is applied on t he incoming water . Specimens with boundary condition A showed larger moisture absorption than ones with boundary condition B. The effect of boundary conditions is more prominent in longer specimens and in specimens made with mortar concrete of larger W/C ratio . General formulation for multi - phase water movement in concrete is presented. A mode l is developed considering the equilibrium of forces, for the liquid water movement drive n by surface tension and pressure a nd resisted by the s hear friction be tween wat e r a nd concrete . Results obtained from the mode l were compared with experimental results a nd they s how very good agreement . Concrete Permeability Maekawa, Koichi, Chairperson Pichai Nimityongskul, Examination Committee Yamaguchi, Hiroki, Examination Committee Government of Japan, Scholarship Donor Asian Institute of Technology. Thesis ; no. ST-91-23 Full-Text http://203.159.5.9/ait-thesis/detail.php?q=B17731 .b10454792 mnait s 240402 2 951012 m a s 0 mnait mnait mnarc 20 40 Barcode : 30050003065421 CREATED : 1995-10-15 RECORD # : i1056939x LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 Barcode : 30050120689285 CREATED : 1995-10-15 RECORD # : i10569406 LPATRON : 1011384 LCHKIN : 2001-03-03 # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 4 TOT RENEW : 1 Barcode : 30050160022496 CREATED : 2016-04-04 RECORD # : i12922390 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 78762 78762 0 0 0 0 MAIN MAIN mnait 2026-08-18 0 AIT Thesis no. ST-91-23 30050003065421 2026-08-18 15:58:27 1 2026-08-18 20 0 0 0 0 MAIN MAIN mnait 2026-08-18 0 AIT Thesis no. ST-91-23 30050120689285 2026-08-18 15:58:27 2 2026-08-18 20 0 0 0 0 MAIN MAIN mnarc 2026-08-18 0 AIT Thesis no. ST-91-23 30050160022496 2026-08-18 15:58:27 1 2026-08-18 40