American Concrete Institute (ACI) has adopted the following working definition of high strength concrete (HSC): Concrete with compressive strength of 41 Mpa or grater but not including concretes made with exotic materials or technologies.
Compressive Strength approaching 138 Mpa has been used in Cast-in-Place buildings in U.S.A.
Roller Compacted Concrete (RCC) is classified as Rollcrete. Lean Concrete, Medium paste content, Rolled Concrete.Rcc has applications in construction of dams, canal linig, Pavements, Roads and Airports.
Self Compacting Concrete
Self Compacting Concrete (SCC) is defined as a category of high performance concrete that has excellent deformability in the fresh state and high resistance to segregation and can be placed and compacted under its self without applying vibration.
Fly ash based self-compacting concretes with 28 days compressive strengths in the range of 60-70 Mpa have been produced by civil Engineering department of IIT, Roorkee.
American Concrete Institute (ACI) defines high performance concrete(HPC) as concrete meeting special combinations of performance and uniformity requirements that cannot always be achieved routinely using constituents and normal mixing, placing and curing practices.
HPC used for the construction of numerous offshore structures and long span bridges throughout the world.
Ready Mix Fly ash Concrete or RMC as it popularly called, refers to concrete that is specifically manufactured for delivery to the customer’s construction site in a freshly mixed and plastic or unhardened state.
If Portland-pozzolana cement (Fly ash based) is substituted in place of ordinary Portland cement or if fly ash added as part replacement of ordinary Portland cement in concrete at the job site, the resulting product is termed as fly ash concrete.
Such fly ash concrete is now used for all civil engineering structural concrete applications and bridges.
Indian Railway authorities heave recently accepted this product for use in Railway Sleepers.
The masonry cement, covered under IS:3466-1988 is manufactured by inter – grinding a mixture of Portland cement clinker with pozzolanic materials such as fly ash and claimed clay pozzolanic materials such as lime atone, conglomerates, Dolomite lime stone dolomite, waste materials like carbonated sludge , mine tailings etc, generally to a fineness greater than that of Ordinary Portland Cement.
The annular space between steel casing and sedimentary rock formation through which oil well has been drilled is sealed off by cement slurry to prevent escape of oil or gas. The cement slurry also seals off any other fissures or cavities in the rock layer. It can be used as an admixture in oil- well cement.
It is an intimately inter-ground mixture of Portland clinker and sly ash with the possible addition of gypsum or an intimate and uniform blending of Portland cement and fly ash. Fly ash used in manufacture of Portland-pozzolana cement should confirm to IS:3812(part 1)-2003.In this type of cement, the fly ash constituent shell not less than 15% and not more then 35% by mass of Portland-pozzolana cement.
Percentage of Production in Portland-pozzolana cement (Fly ash based) In India has steadily increased from 17.31% in 1989-90, to 60.12% in 2006-07 and to 67% in 2010-11.
Portland-pozzolana cement (Fly ash based) produces less heat of hydration and offers greater resistance to the attack of aggressive waters than Ordinary Portland Cement.
In this type of cement particularity useful in marine and hydraulic Construction and other mass concrete structures.
D – Dead loads; L – Live loads; F – Fluid loads: W– Wind loads;
S – Snow loads; E – Earthquake loads; T - Thermal Loads
H – Earth pressure loads;
The structural members are connected together by providing different types of joints or supports. Most common types of supports are pin-jointed or hinged, roller support and fixed support. Every support provide some restraint to the structural members connected to it. A pin-jointed support will develop a force on the connected member
because it does not allow it to translate in any direction whereas the roller support can provide the reaction only in the direction other than movement of roller. A fixed support provide restraint to translation as well as rotation, therefore it has 3
reactions (2 forces and one moment).