Reinforced concrete is a composite material that combines concrete's low tensile strength with reinforcement bars' high tensile strength. The reinforcement, usually steel rebar, is embedded in concrete before it sets to resist tensile stresses that could cause cracking or failure. Modern reinforced concrete can use varied reinforcing materials like steel, polymers, or composites alone or with rebar. Reinforced concrete provides strength and durability for construction.

1. Submittedby:-ArchitaSaspara
BhavikaBhargava
GarvitaDhaddha
KantilalSuthar
KapilPansuriya
KartikPatel
RajendraSharma

4.  Reinforcedconcrete(RC) is acompositematerialin whichconcrete'srelatively lowtensile
strengthandductilityarecounteractedbytheinclusion ofreinforcementhaving higher tensile
strengthand/orductility.
 The reinforcementis usually,thoughnotnecessarily, steel reinforcing bars(rebar) andis usually
embeddedpassively in theconcretebeforethe concretesets.
 Reinforcingschemesaregenerally designed toresist tensilestressesin particularregions ofthe
concretethatmight causeunacceptablecrackingand/orstructuralfailure.
 Modern reinforcedconcretecancontainvaried reinforcingmaterialsmadeof steel,polymersor
alternatecompositematerialin conjunctionwithrebarornot.
 Reinforcedconcretemayalsobepermanentlystressed(in compression), soastoimprovethe
behaviourofthe finalstructureunderworkingloads.

5.  Forastrong,ductileanddurableconstructionthe reinforcementneedstohavethe following
propertiesatleast:
◦ High relative strength
◦ High toleration of tensile strain
◦ Good bond to the concrete, irrespective of pH, moisture, and similar factors
◦ Thermalcompatibility, not causing unacceptablestresses in response to changingtemperatures.
◦ Durability in the concreteenvironment,irrespective of corrosion or sustained stress for example.

8.  Concrete containing a hydraulic cement, water , aggregate, and discontinuous discrete fibers is
calledfiberreinforced concrete.
 Fiberscan bein formofsteelfiber,glassfiber,naturalfiber,syntheticfiber.
 Main role of fibers is to bridge the cracks that develop in concrete and increase the ductility of
concreteelements.
 Improvement onPost-Crackingbehaviorofconcrete
 ImpartsmoreresistancetoImpactload
 controlsplasticshrinkagecrackinganddryingshrinkagecracking
 Lowersthepermeabilityofconcretematrixandthusreducethebleeding ofwater.

11.  Lightweight concreteis aspecial concretewhich weighs lighterthanconventionalconcrete.
 Densityofthisconcreteisconsiderablylow (300 kg/m3to 1850kg/m3) whencomparedto
normalconcrete(2200kg/m3to 2600kg/m3).
 ThreetypesofLWC:
 Light weight aggregate concrete
 Aerated concrete
 No – finesconcrete
 Lightweight aggregate concrete-UK, France&USA
 Aeratedconcrete-Scandinaviancountries
 No– finesconcreteisless popular

16. Fly ashcould beanexpensivereplacement forPortlandcement in concreteandusing it,improves
strength,segregation andease ofpumpingconcrete.
 The rateofsubstitutiontypicallyspecified is aminimum of 1to 1½poundsofflyashto1 poundof
cement
 Fly Ash particlesprovideagreaterworkabilityofthepowderportionofthe concretemixturewhich
resultsin greaterworkabilityofthe concreteanda lowering ofwaterrequirementforthesame
concreteconsistency.

18.  High strength concrete and high-performance concrete are not synonymous because
strength and performance of concrete are different properties of concrete. High-strength
concrete is defined based on its compressive strength at a given age.
 While high strength concrete is defined purely on the basis of its compressive strength,
Mehta and Aitcin defined the high-performance concrete (HPC) as concrete mixtures
possessing high workability, high durability and high ultimate strength.
 ACI defined high-performance concrete as a concrete meeting special combinations of
performance and uniformity requirements that cannot always be achieved routinely using
conventional constituents and normal mixing, placing, and curing practice.

20.  High strengthofconcreteis achievedbyreducing porosity,in-homogeneity,andmicro-cracksin
the hydratedcement pasteandthe transitionzone.
 Thereisareductionofthe thicknessofthe interfacialtransitionzonein high-strengthconcrete.
 Thedensificationofthe interfacialtransitionzoneallowsforefficient loadtransferbetween the
cement mortarandthe coarseaggregate,contributingtothe strengthoftheconcrete.
 Forvery high-strengthconcretewherethematrixis extremelydense, a weakaggregate may
becomethe weaklink in concretestrength.

21.  No-finesconcreteis obtainedbyeliminating thefinematerialsand,fromthe normalconcretemix.
 Thesingle-sizedcoarseaggregatesaresurroundedandheld togetherbya thinlayerofcement
pastegiving strengthofconcrete.
 The advantagesofthis typeof concreteare:
◦ Lower density;
◦ Lower cost due to lower cement content;
◦ Lower thermal conductivity relativelylow dryingshrinkage;
◦ No segregation and capillary movementof water;
◦ Better insulating characteristics than conventional concrete becauseof the presence of large voids.

24.  Ready-mixconcreteisconcretethatis manufacturedin afactoryor batchingplant,accordingtoa
set recipe, andthendelivered toaworksite, bytruckmountedin–transitmixers.
 This resultsin aprecisemixture,allowing specialtyconcretemixturestobedeveloped and
implementedon constructionsites.
 The firstready-mixfactorywasbuiltin the1930s,butthe industrydid notbegin toexpand
significantlyuntilthe 1980s,andit hascontinuedtogrowsincethen.
 Ready-mixconcreteis sometimespreferredover on-siteconcretemixing becauseoftheprecision
ofthe mixtureandreducedworksiteconfusion.
 However, using apre-determinedconcretemixturereducesflexibility,bothin thesupplychainand
in theactualcomponentsoftheconcrete.

25.  Ready-mixconcreteis alsoreferredas thecustomizedconcreteproductsforcommercial purpose.
 Ready-mixconcrete,orRMCas itis popularlycalled,referstoconcretethatis specifically
manufacturedfordelivery tothe customer'sconstructionsitein afreshlymixedandplasticor
unhardenedstate.
 Concreteitself is a mixtureofPortlandcement, waterandaggregatescomprising sandandgravel or
crushedstone.
 In traditionalworksites,eachof thesematerialsis procuredseparatelyandmixedin specified
proportionsatsitetomake concrete.
 Ready-mixconcreteis boughtandsold byvolume -usuallyexpressedin cubic meters(cubic yards
in theUS).
 Ready-mixconcreteis manufacturedundercontrolledoperationsandtransportedandplacedat
siteusing sophisticatedequipment andmethods.

30.  RCC(ReinforcedCement Concrete)is thecombinationofusing steel andconcreteinsteadofusing
onlyconcretetooffsetsomelimitations.
 Concreteis weakin tensile stresswith comparedtoits compressive stress.
 Tooffsetthislimitation,steel reinforcementis used in theconcreteattheplacewherethe sectionis
subjected totensilestress.
 Steel is very strongin tensile stress.
 The reinforcementis usuallyroundin shapewith approximatesurfacedeformationis placed in the
formin advanceofthe concrete.
 Whenthe reinforcementis surroundedbythe hardenedconcretemass,it formanintegral partof
the member.
 The resultantcombinationoftwomaterialsareknownasreinforcedconcrete.
 In thiscasethecross-sectionalareaofthe beamor otherflexuralmember is greatlyreduced.

32.  Reinforcedconcretehasahigh compressive
strengthcomparedtootherbuilding
materials.
 Due totheprovided reinforcement,
reinforcedconcretecanalsowithstanda
goodamounttensilestress.
 Fire andweatherresistanceofreinforced
concreteisfair.
 The reinforcedconcretebuilding system is
moredurablethananyotherbuilding
system.
 Reinforcedconcrete,asa fluidmaterialin the
beginning, canbeeconomicallymoulded
intoa nearlylimitless range ofshapes.
 The maintenancecost ofreinforcedconcrete
isvery low.
 In structurelike footings,dams,piersetc.
reinforcedconcreteis themost economical
constructionmaterial.
 It actslike arigid member withminimum
deflection.
 As reinforcedconcretecanbemouldedto
anyshape required,it is widely usedin
precaststructuralcomponents.It yields rigid
memberswithminimum apparent
deflection.
 Comparedto theuseof steel in structure,
reinforcedconcreterequiresless skilled
labourforthe erection ofstructure.

34.  Generally therearetwotypesofsteelbarsavailablein themarket.
◦ Mild steel bars
◦ Deformed steel bars

35.  Mild steel barsareused fortensilestressofRCC(Reinforcedcement concrete)slabbeams etc.in
reinforcedcement concretework.
 Thesesteelbarsareplainin surfaceandareroundsections ofdiameterfrom6 to50 mm.
 Theserodsaremanufacturedin long lengths andcanbe cutquicklyandbebenteasilywithout
damage.

36.  Reinforcementbarsin accordancewith standardISNo.432part-Icanbe classified intofollowing
types.
◦ Mild Steel Bars: Mild steel bars can be supplied intwo grades
 Mildsteel bars grade-Idesignated as Fe 410-S orGrade 60
 Mildsteel bars grade-IIdesignated as Fe-410-o orGrade 40
◦ Medium Tensile Steel Bars designated as Fe- 540-w-htor Grade75
 GradeII Mild steelbararenotrecommendedforusein structureslocatedin earthquakezones
subjecttosevere damageandforstructuressubjecttodynamicloading(otherthanwindloading)
such asrailwaysandhighwaysbridges.
 Everylot orconsignment ofmild steel barsbroughtatthe siteofworkshouldbetestedin
laboratorybeforeuse in thework.However forsmall workone canusemild steel barson thebasis
ofverifying testsresults madebymanufacturerin his own laboratory;whichareavailablewith
supplier.
 Some ofmanufacturersstampedMS barsgradewith theirmake/name andalsogivecertification
oftestandgrade.Onthe basisofthe aboveinformationyoucanstoremild steel barsgrade-wiseat
the siteofwork.

38.  As deformedbarsarerodsofsteels providedwithlugs, ribsordeformationonthe surfaceofbar,
thesebarsminimizeslippagein concreteandincreases thebondbetween thetwomaterials.
 Deformedbarshavemoretensile stressesthanthatofmild steel plainbars.
 Thesebarscanbeusedwithoutend hooks.
 The deformationshouldbespacedalong thebaratsubstantiallyuniformdistances.
 Tolimit cracksthatmaydevelop in reinforcedconcretearoundmild steel barsduetostretching of
barsandsome loseofbondunderloadit is commontousedeformedbarsthathaveprojecting ribs
oraretwistedtoimprovethe bondwith concrete.

39.  Thesebarsareproducedin sectionsfrom6 mm to50 mm dia.
 In additionthe strengthofbondsofdeformedbarscalculatedshouldbe40 to80% higher than
thatofplain roundbarsofsamenominalsize.
 Andit hasmoretensile stressthanthatof plainroundbarsofsamenominalsize.
 Cold twisteddeformed(RibbedorTorSteel Bars)barsarerecommendedas bestqualitysteel bars
forconstructionworkbystructuralEngineer.

40.  TMT Bars,Thermo mechanicallytreatedbarsarehigh strengthdeformedsteel barsusedin
reinforcedcement concrete(RCC) workmanufacturedwith thehelp ofadvancementof
technology.
 TMT barsarelatestproductionin MS steel barsandhavesuperiorpropertiessuch asstrength,
ductility,welding ability,bending abilityandhighest qualitystandardsatinternationallevel.

41.  High strengthdeformedbarsIS:1786-1985aresteel barswhich areprovided withlugs, ribs,
projectionordeformationonthe surfaceandareproducedin formofcold twisteddeformedbars.
 Thesebarsareextensively usedforreinforcementpurposesin aconstruction.
 Due toribsor projectionsonthe surface,thesesteel barsminimize slippagein concreteand
increasethebondbetween twomaterialsi.e. betweencement concreteandsteelbars.
 The deformedbarshavemorecompressive andtensile stressthanthatofmild steel plainbars.
High strengthdeformedbarshaveimprovedanchorage;thereforetheycanbeusedwithoutend
hooksor bentupends ofbars.

42.  This reduceslabourforfabricationofsteelreinforcement. Thedeformationis spacedon barat
uniformdistances.
 Thesebarsareproducedin sizesor sectionsfrom4 mm to50 mm in diameter.
 Generally cracksdevelop in reinforcedconcretearoundmild steelbarsdue tostretchingofbars,
lossofbondunderthe load.
 Tominimizethis problem,deformedbarshaving projecting ribsortwistedsurfacewhich improves
the bondwith theconcreteshouldbeusedin RCCwork.

45.  Thereareseveral reasonsforbending bars:
◦ Whereanchoragecannot be provided to a straight lengthwithin the available concreteshape or size, it
may benecessary to bend a 180°hookor 90°cog on the end.
◦ Hooks and cogs are neverscheduled unless they areshown onthe engineer’s drawings.
◦ Wherecontinuityof strength is requiredbetween two intersecting concretemembers, thebar will be bent
to allow this stress transfer.
◦ Such bends are neverscheduled unless they areshown onthe engineer’s drawings.
◦ Whereties, stirrups, ligatures or spirals (called ‘fitments’ by theindustry) enclose longitudinal bars ina
beam or a column, the fitment will be scheduled to match the shape of the surroundingconcrete.
◦ Mostly the shapeis defined by the concretesurface and thespecified cover. Theactual shape is definedby
the scheduler, provided the designer’s intentions are given in the drawings.
◦ Thedesigner must indicateif cogged or hookedends are required.
◦ Whereintersecting reinforcementis likelyto clash, or whereparallel bars requirelapping, the scheduler
will decide whetheror not to provide small offsets.

51.  A spreadfooting(orisolatedor pad)footingis providedto supportanindividualcolumn.
 A spreadfootingis circular,squareorrectangularslab ofuniformthickness.
 Sometimes,itis steppedorhunchedto spreadthe loadover alargearea.

73.  RCCStructuresarenothingbutreinforcedconcretestructures.
 RCCstructureis composedofbuilding componentssuch asFootings, Columns,Beams, Slabs,
Staircaseetc.
 Thesecomponentsarereinforcedwithsteel thatgive stabilityto thestructure.
 Staircaseisonesuch importantcomponentin aRCCstructure.

74.  Straight stairs
 Dog-legged stair
 Open newel stair
 Geometrical stair

75. Straight stairs

76. Dog-leggedstair

77. Opennewelstair

78. Geometrical stair