By
Sourav Dutta
Manager-Civil
Ion Exchange India Limited
Now-a-days for controlling rust/corrosion of rebar some extra treatment is being carried out on rebar, making it more resistant to rusting/corrosion under unfavorable circumstances. Some of these treated rebars normally used are: (1) Fusion bonded epoxy coated rebar, (2) Cement-polymer composite coated rebar,(3) Corrosion resistant steel (CRS) rebar. The following comparison is being made aiming to give a clear cut idea on advantages/disadvantages of each type, which might help and give an idea to construction industry for decision making of selection of any particular type.
Comparison of Epoxy coated rebar vs CPCC rebar vs CRS rebar
Manufacturing in RCC Construction – Prefabricated rebars
By
Priyanka Gupta
Three decades back, a construction site was a place where all building materials were brought in fabricated or mended as per need and then used. For example cement, sand, stonechips and water was assembled at construction site; mixed as per design and used. Brick kilns were the only manufacturing/ prefabrication done in advance for construction. Storing of inventory at construction sites wasvery much prevalent.
The concept of factories and automobile industry like ‘lean engineering’, ‘just in time delivery’ and prefabrication have changed the very picture of construction site. But till early 2000 prefabrication in construction rebars was only in concept. Around 2010 prefabrication of TMT rebars started in India and now it has become indispensable for both large as well as small scale project.
Comparison Between CPCC, FBEC & CRSD
By
Priyanka Gupta
Before doing the comparison study lets know what these terms mean.
CPCC – Cement-Polymer Composite Coated Rebars
FBEC – Fusion Bonded Epoxy Coated Rebars
CRSD – Corrosion Resistant Steel Deformed Rebars
1.0 Corrosion Control of Reinforcement bars (Rebars)
40% of failure of structures is on account of corrosion of embedded steel reinforcement in concrete. Therefore corrosion control of steel reinforcement is a subject of paramount importance.First and foremost for corrosion control is the good quality of concrete through good construction practices.
Rust / Corrosion of Reinforcement Bars – A challenge to overcome
By
Mr.Sourav Dutta
Manager (Civil)
Tata Steel Ltd
Rusting/Corrosion are mainly caused due to:
1. Prolonged exposure of rebar to atmosphere/rainfall without any precaution.
2. Aggressive/saline/toxic environment.
RUST is caused by the reaction of air (O2) and moisture (H2O), and it is a common and natural phenomenon for most steel products. IT SHALL NEVER BE CAUSE OF CONCERN/REJECTION OF REBAR, AS PER BIS.
Fig : Guideline of BIS1786-2008
Problems of using High Grade Steel in Constructions
Presented by:
1) Prof.M.V.Kuriakose B.Tech(Ed), M.I.E. (Retd.Principal, Govt.Polytechnic, Perinthalmanna)
2) Mr.Jismon Issac B.E (Mech) A.I.E, MBA
[Prof.M.V .Kuriakose is having around 35 years of expertise in Structural Engineering and Designing. He is an active member of Lensfed.]
[Mr.Jismon Issac has 13 years of experience in the manufacturing & Quality testing of Construction Steel bars especially High grade TMT steel bars]
Now days some contractors report a tendency among few design Engineers that they specify grade Fe-500 or higher steel in residential buildings, citing its high strength. If they design buildings considering the use of Fe 500 steel in construction, it could help reduce the volume of steel used and reduce the column size.
The rosy part aside, Fe 500 grade steel could pose quite a few site specific issues during construction, especially for small builders. Considering the reported failures and problems with grade Fe-500 or higher, it is advisable to use Fe 415 in residential and commercial buildings and Fe500 could be used only when the entire design is made according to that grade. This is explained below;