Non-Destructive Imaging of Water Permeation through Cementitious Materials Using MRI

Non-Destructive Imaging of Water Permeation through Cementitious Materials Using MRI

In this study, water permeation through building material materials was discovered exploitation resonance imaging (MRI). The influence of cement sort on the resonance signal was studied after deciding the parameters needed for imaging. Consequently, adequate imaging of water pervasive through hardened cement paste (HCP) created with white hydraulic cement was achieved, whereas water permeation through standard Portland cement-based HCP yielded poor signal. HCPs maintained at varied levels of ratio (RH) were discovered, and also the signal was detected solely from those maintained at associate RH of upper than eighty fifth. The water permeation depths in HCP were discovered by exploitation tomography, and also the measured depths were compared to those measured via a spraying water detector on the split surface of the specimens. As a result, smart agreement was confirmed between the 2 ways. in addition, tomography was applied to concrete specimens; though it absolutely was found that water wasn't detected once a light-weight mixture was used, water permeation through concrete with rock mixture was detectable via tomography. tomography can facilitate in understanding however water permeation causes and accelerates concrete deterioration like re bar corrosion and phase change and thawing..

About The Author:

Sp.Aswinpalaniappan M.E.,*

Member of American Concrete Institute

Sri Raaja Raajan College of Engineering and Technology

Karaikudi, Tamil Nadu 630301

Practical Aspects of the Design and Construction of a Small Cable Roof Structure

Practical Aspects of the Design and Construction of a Small Cable Roof Structure

DOI: 10.4236/ojce.2017.73031    

Author(s)    Vinicius Fernando Arcaro, Luiz Carlos de Almeida

Affiliation(s)

University of Campinas, Campinas, Brazil.

ABSTRACT

Cable roof structures have only become widespread in large span structures in the latter part of the twentieth century. However, they still represent a relatively new form of roof construction, especially as in the present case of a small span innovative structural solution. The contribution of this text to the structural engineering community lies in the increased interest in building simple cable roof structures. Since its completion in September 1996, this small cable roof structure has been recognized as an interesting architectural and structural example. The text describes aspects of the design and construction of a small cable roof that was designed as a roof for an open-air theater stage for the city of Sao Jose do Rio Pardo, Sao Paulo, Brazil. A cable network, in the shape of a hyperbolic paraboloid surface, is anchored in a reinforced concrete edge ring. The projection of the ring’s axis onto the ground plane is an ellipse. Workers with specialized training were employed in the various stages of the construction, which was completed in September 1996.

KEYWORDS

Cable Roofs, Hypar Roofs, Tension Structures

Effect of Eccentric Shear Stiffness of Walls on Structural Response of RC Frame Buildings

Effect of Eccentric Shear Stiffness of Walls on Structural Response of RC Frame Buildings

DOI: 10.4236/ojce.2017.74035    

Author(s)    

Muhammad Umair Saleem

Affiliation(s)

Department of Civil and Environmental Engineering, College of Engineering, King Faisal University, Al-Ahsa, Saudi Arabia.

ABSTRACT

Current research study consists of determining the optimum location of the shear wall to get the maximum structural efficiency of a reinforced concrete frame building. It consists of a detailed analysis and design review of a seven-story reinforced concrete building to understand the effect of shear wall location on the response of reinforced concrete structures when subjected to different earthquake forces. Three trail locations of shear walls are selected and their performance is monitored in terms of structural response under different lateral loads. Required objectives are achieved by obtaining design and construction drawings of an existing reinforced concrete structure and modeling it on Finite Element Method (FEM) based computer software. The structure is redesigned and discussed with four different configurations (one without shear wall and three with shear walls). Main framing components (Beams, Columns and Shear walls) of the superstructure are designed using SAP 2000 V. 19.0 whereas substructure (foundation) of RC building was designed using SAFE. American Concrete Institute (ACI) design specifications were used to calculate the cracked section stiffness or non-linear geometrical properties of the cracked section. Uniform Building Code (UBC-97) procedures were adopted to calculate the lateral earthquake loading on the structures. Structural response of the building was monitored at each story level for each earthquake force zone described by the UBC-97. The earthquake lateral forces were considered in both X and Y direction of the building. Each configuration of shear wall is carefully analyzed and effect of its location is calibrated by the displacement response of the structure. Eccentricity to the lateral stiffness of the building is imparted by changing the location of shear walls. Results of the study have shown that the location of shear wall significantly affects the lateral response of the structure under earthquake forces. It also motivates to carefully decide the center of lateral stiffness of building prior to deciding the location of shear walls.

KEYWORDS

Reinforced Concrete Buildings, Computer aided Modelling, Shear Walls, Stiff-ness, Deformations

A PARTIAL REPLACEMENT OF COARSE AGGREGATE BY SEASHELL

A PARTIAL REPLACEMENT OF COARSE AGGREGATE BY SEASHELL

Partially replacement of coarse aggregate in sea shell used material for   creating  new product.

In this project we are going to replace of coarse aggregate of 40% to sea shell 60% is to be fixed.

When the coarse aggregate is replaced with 10% 20% 30%  by seashell.

When the design mix used to execute the  project is m20 grade of concrete.

The m20 grade concrete refer code book for indian standard code for conventional and seashell concrete.

Water cement ratio is maintained for this mix design is 0.5.

About The Author:

Sp.Aswinpalaniappan M.E.,*

Member of American Concrete Institute

Sri Raaja Raajan College of Engineering and Technology

Karaikudi, Tamil Nadu 630301

LIST OF SYMBOLS

LIST OF SYMBOLS

1. A                     =           Area (mm²)
2. A_c                       =           Area of concrete (mm²)
3. A_g                       =           Area of section (mm²)
4. D                  =           Overall depth(mm)
5. d                    =           Effective depth (mm)
6. Fy                  =           Characteristic strength of steel (N/mm²)
7. Fck                =           characteristic cpmpressive strength (N/mm²)
8. UL                 =           Factored Load (KN)
9. LL                 =           Live load           (KN)
10. T                   =            Shear stress in concrete (N/mm²)
11. t_v                  =            Nominal shear ( N/mm²)
12. M.F                =            Modification factor
13. B.V                 =            Basic value
14. Vu                  =            Design shear stress force (N/mm²)
15. W                   =            Total load (Kn)
16. Wu           =            Factored load (KN)
17. Ø A_st         =       Area of steel Required
18. Ø A_sc        =       Area of one bar
19. Ø W         =       Total load on the slab (or) Beam
20. Ø w           =       Uniformly distribution load/meter length
21. Ø l_eff          =       Effective length
22. Ø d            =       Effective Depth
23. Ø M_max      =       Maximum shear force
24. Ø τ_v           =       Nominal shear force
25. Ø τ_c            =       Safe shear force
26. Ø S_v           =       Stirrups spacing along the length of the bar
27. Ø M.R      =       Moment of Resistance
28. Ø F_y           =       Characteristic strength of steel
29. Ø D.L       =       Dead Load
30. Ø I.L         =       Imposed Load
31. Ø L_x            =       Effective length along shorter span
32. Ø L_y            =       Effective length along long span
33. Ø Ф           =       Diameter of bar
34. Ø M.F       =       Modification of Factor
35. Ø B.V       =       Basic Value
36. Ø P           =       Axial load
37. Ø SBC      =       Soil Bearing Capacity
38. Ø BM       =       Bending Moment
39. Ø Ms        =       Modular ratio
40. Ø K           =       Constant
41. Ø L           =       Clear span
42. Ø A           =       Area of footing or column
43. Ø b            =       Breadth
44. Ø F_ck         =       Characteristic compressive strength of concrete
45. Ø F_y                    =       Characteristic strength of steel
46. Ø W_u        =       Design load
47. Ø A_sc        =       Area of compression steel
48. Ø A_g         =       Area of cross section
49. Ø P_u                          =       Axial load on the member
50. Ø λ           =       Slenderness ratio of the column
51. Ø l_d           =       Development length

About The Author:

Sp.Aswinpalaniappan M.E.,*

Member of American Concrete Institute

Sri Raaja Raajan College of Engineering and Technology

Karaikudi, Tamil Nadu 630301

TO STRENGTHING COMPRESSIVE STRENGTH OF CONCRETE BY PARTIALY REPLACEMENT OF FINE AND COARSE AGGREGATE USING BY DEMOLISED WASTE WITH FIBERS

TO STRENGTHING COMPRESSIVE STRENGTH OF    CONCRETE BY PARTIALY REPLACEMENT OF  FINE AND COARSE AGGREGATE USING                                 BY DEMOLISED WASTE WITH FIBERS

Growing demand of infrastructure to meet the need of increased population to city centers result in construction of new building and roads this result in increased consumption of natural aggregate also produce huge quantum of demolished concrete. This waste is generally dumped in landfills which are at far distances in urban area. Transportation of this waste thus creates the economical and environment problems to overcome these problems idea of recycled aggregate has started and is active area of research. Recycled of this debris can make a contribution to reduce to total environment impact of a building sector. me demolished waste components include Portland cement concrete.

          In this study to evaluate the performance and strength characteristic of replacement concrete by demolition waste partial replacement of demolish waste tiles and crushing rock powder instead of course aggregate respective for our project 10% ,15% , 20% Replacement of demolished waste concrete cube  molded  & performances are checked compare with concrete demolish waste concrete obtained 24.4KN/m2  for 2o% replacement of coarse and fine aggregate replacement by Tiles and Crusher rock powder.

About The Author:-

Sp.Aswinpalaniappan M.E.,*
Member of American Concrete Institute
Sri Raaja Raajan College of Engineering and Technology
Karaikudi, Tamil Nadu 630301