Design of Masonry Structures Multiple Choice Questions and Answers for PDF - Preparation for Engineering PDF

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DesignofMasonryStructuresMultipleChoiceQuestions andAnswersforPDF 2.Iftheratioofcentertocentrespacingofintersectingwallstoactualthicknessof intersectingwallismorethn20,thenthestiffeningcoefficientforwallproperwillbe a)0 b)between0and1 c)1 d)greaterthan1

Ans:d 7.Maximumslendernessratioofloadbearingwallsforadwellinghavingmorethan2stores (i)shallnotexceed12iflimemortarisused (ii)shallnotexceed18ifcementlimemortar1:2:9isused (iii)shallnotexceed24ifcementmortar1:6isusedOfthesestatements a)(i)and(ii)arecorrect b)(ii)and(iii)arecorrect c)(i)and(iii)arecorrect d)(i)and(ii)and(iii)arecorrect

Ans:a 8.Whereastructuralcomponentorasystemisprovidinglateralsupporttofiveormorewallsorcolumns, thelateralloadtoberesistedmaybetakenas a)4percent b)5percent c)6percent d)7percent ofthetotalverticalloadonthemostheavilyloadedwallorcolumninthegroup.

Ans:d 9.Theeffectiveheightoffreestandingnonloadbearingwallandcolumnrespectivelywillbe a)1.OHand1.OH b)1.5Handl.5H c)2.0Handl.5H d)2.0Hand2.0H whereHistheheightofwallorcolumnbetweencentresofsupports. Ans:d 10.IfHistheheightofwallbetweencentresofsupports,thentheeffectiveheightof wallwhereconcretefloorshaveabearingonwallirrespectiveofthedirectionofspanwillbe a)0.75H

b)0.85H c)1.0H d)1.5H Ans:a 11.Thethicknessofeachleafofacavitywallshallnotbelessthan a)5cm b)7.5cm c)10cm d)15cm Ans:b 12.Ifthehorizontalcrosssectionalareaofawallis1200cm2,thenthebasicstressshallbemultipliedbya reductionfactorequalto a)06 b)0.75 c)0.85 d)0.95 Ans:c 13.Afreestandingbrickwall20cmthickissubjectedtoawindpressureof75kg/m2.Themaximumheight ofwallfromstabilityconsiderationis a)0.64m b)0.96m c)1.28m d)1.5m Ans:a 14.Thebendingstressinawallorcolumnsubjectedtoeffectiveverticalloadneed notbeconsidered,iftheeccentricityratiois a)lessthanorequalto1/24 b)lessthanorequalto1/6 c)morethan1/24 d)lessthanorequalto1/12 Ans:a 15.AssertionA:Foreccentricityratioexceeding1/6,effectivethicknessofmasonrywillgetreduced. ReasonR:Foreccentricityratioexceeding1/6,therewillbetensionononesideofthemember. Selectyouransweraccordingtothecodesgivebelow: a)BothAandRaretrueandRisthecorrectexplanationofA. b)BothAandRaretrueandRisnotthecorrectexplanationofA. c)AistruebutRisfalse. d)AisfalsebutRistrue. Ans:a

16.Iftheeccentricityratioismorethan1/24,thenincreaseinthepermissiblestressin thedesignofwallsubjectedtoeccentricloadingaspercodeis a)10% b)25% c)331/3% d)50% Ans:b 17.Fordesigningmasonrycomponentsofastructure,seismicforcesprovisioninthe designcalculationisnotnecessaryforbuildingsconstructedin a)ZoneIonly b)ZoneIandII c)ZoneI,IIandIII d)ZoneI,II,IIIandIV Ans:b 18.Themodeoffailureofaveryshortmasonrymemberhavingh/tratiooflessthan4isby a)shear b)verticaltensilesplitting c)buckling d)anyoftheabove Ans:a 19.AssertionA:Fromconsiderationofstructuralsoundnessandeconomyofdesign,mostcodescontrolthe maximumslendernessratioofmasonrywallsandcolumns. ReasonR:Bycontrollingthemaximumslendernessratio,failureisbyexcessivestressandnotbybuckling. Selectyouransweraccordingtocodesgivenbelow: a)BothAandRaretrueandRisthecorrectexplanationofA. b)BothAandRaretruebutRisnot.thecorrectexplanationofA. c)AistruebutRisfalse. d)AisfalsebutRistrue. Ans:a 20Thetimberfloornotspanningonthemasonrywallbutproperlyanchoredtothewallgives a)lateralrestraintbutnotrotationalrestraint b)rotationalrestraintbutnotlateralrestraint c)bothlateralandrotationalrestraints d)neitherlateralnorrotationalrestraint Ans:a 21.Fullrestraintisprovidedby (i)foundationfootingofawall (ii)timberfloorspanningonthewallandanchoredtothewall (iii)RCCslabwithaminimumbearingof10cmonthewallOfthesestatements a)(i)and(iii)arecorrect

b)(i)and(ii)arecorrect c)(ii)and(iii)arecorrect d)(i),(ii)and(iii)arecorrect Ans:d 22.Minimumthicknessofstiffeningwallfor1to3storeysshallnotbelessthan a)10cm b)15cm c)20cm d)30cm Ans:a 23.Whichofthefollowingwillgivehigherratioofbrickworkstrengthtomortarstrength? a)1:%:3 b)1:Vz:4>/2 c)1:1:6 d)1:2:9 Ans:d 24.AssertionA:Limebasedmortarsgivehigherratioofbrickworkstrengthtomortarstrengthascompared tononlime mortar. ReasonR:Limebasedmortarshavelowerbondstrengthascomparedtononlimemortars. Selectyouransweraccordingtothecodesgivenbelow: a)BothAandRaretrueandRisthecorrectexplanationofA. b)BothAandRaretruebutRisnotthecorrectexplanationofA. c)AistruebutRisfalse. d)AisfalsebutRistrue. Ans:c 25.Formasonryworkwithsolidbricks,consistencyofmortarshouldbe a)5to8cm b)9to13cm c)14to18cm d)19to23cm Ans:b 26.Waterretentivityforbrickmasonryshouldnotbelessthan a)50% b)60% c)70% d)80% Ans:c 27.MinimumcompressivestrengthinN/mm2forH1typemortarusedformasonryis

a)3 b)5 c)7.5 d)10 Ans:d 28.Richcementmortarsaremoreliabletocrackingascomparedtoleanmortarsbecauserichmortars have a)highshrinkage b)lessstrength c)both(a)and(b) d)noneofabove Ans:a 29.Cementmortarsricherthan1:3arenotusedinmasonrybecause (i)thereisnogaininstrengthof masonry(ii)thereishighshrinkage(iii)theyarepronetosegregationOfthesestatements a)Only(ii)iscorrect b)(i)and(ii)arecorrect c)(ii)and(iii)arecorrect d)(i),(ii)and(iii)arecorrect Ans:b 30.Forearthquakeresistantmasonrybuildings,theverticaldistancebetween openingsoneabovetheotherinaloadbearingwallshallnotbelessthan a)50cm b)60cm c)75cm d)100cm Ans:b 31.Forearthquakeresistantmasonrybuildings,whereseismiccoefficientislessthan0.08,thehorizontal distancebetweentwoopeningsshallnotbelessthan a)Vtxheightofshorteropening b)Vtxheightoflongeropening c)Axheightofshorteropening d)Vixheightoflongeropening Ans:a 32.Considerthefollowingstatementsregardingbandstobeprovidedforstrengtheningmasonryworkin masonrybuildingsconstructedinzoneIII,IVandV.(i)Lintelbandisprovidedatlintellevel onpartitionwalls,(ii)Gablebandisprovidedattopofgable masonrybelowthepurlins,(iii)Thebandsshallbetofullwidthofthe wallandnotlessthan7.5cmin depth,(iv)Thebandsshallbemadeofreinforced

concreteonly.Ofthesestatements,thecorrectstatementsare a)(i)and(ii) b)(i)and(iii) c)(ii)and(iv) d)(ii)and(iii) Ans:d 38.Inacavitywall,bothleavesofwhichareloadbearing,theeffectivethicknessistakenas a)sumofthicknessofbothleaves b)twothirdofthesumofthicknessofboththeleaves c)actualthicknessofthestrongerleaf d)largerof(b)and(c) Ans:d 39.AssertionA:Limitingvalueofslendernessratioforacolumnislessthanthatofawall. ReasonR:Acolumncanbucklearoundeitherofthetwohorizontalaxeswhileawallcanbucklearound onlyoneaxis.Selectyouransweraccordingtothecodesgivenbelow: a)BothAandRaretrueandRisthecorrectexplanationofA. b)BothAandRaretruebutRisnotthecorrectexplanationofA. c)AistruebutRisfalse. d)AisfalsebutRistrue. Ans:a 40.Considerthefollowingstatementsregardingprovisionofchasesinmasonry, (i)Nochaseshouldbepermittedinahalfbrickloadbearingwall, (ii)Verticalchasesshouldnotbecloserthan2minanystretchofawall, (iii)Chasesshouldbeprovidedneartobearingsofbeamsandlintels.Ofthesestatements a)(i)and(ii)arecorrect b)(i)and(iii)arecorrect c)(ii)and(iii)arecorrect d)(i),(ii)and(iii)arecorrect Ans:a 41.Considerthefollowingstatements: Theuseofrelativelyweakmortar 1.willaccommodatemovementsduetoloadsand,crackingifany,andwillbedistributedasthinhaircracks whicharelessnoticeableorharmful. 2.willresultinreductionofstressesduetodifferentialexpansionofmasonryunits. Ofthesestatements a)1aloneiscorrect b)2aloneiscorrect c)both1and2arecorrect d)neither1nor2iscorrect Ans:c

42.Inthecaseofpanelwallsubjectedtohorizontalloadsatrightanglestotheplaneofthewall,withthe mortarnotleanerthanMltype,tensilestressinbendingintheverticaldirectionmaybeallowedtotheextent of a)0.4kg/cm2 b)0.7kg/cm2 c)1.0kg/cm2 d)1.2kg/cm2 Ans:c 43.Forstrengtheninga50mlongand5mhighstraightcompoundwallbuiltinbrickwork,whichoneofthe followingwouldbemostsuitable? a)providingbuttressesatcertainintervals b)providingadeeperfoundation c)usingarichermortar d)usingstrongerbricks Ans:a 44.Considerthefollowingstatements:Sandinmortarisneededfor 1.decreasingthequantityofcement. 2.reducingshrinkage. 3.decreasingthesurfaceareaofthebindingmaterial. 4.increasingthestrength. Ofthesestatements: a)2,3and4arecorrect b)1,2and3arecorrect c)1,3and4arecorrect d)1,2and4arecorrect Ans: 45.Considerthefollowingstatements: Ahighlimecontentinacompositecementlimemortarresultsin 1.slowhardening. 2.quicksetting. 3.weakermortar.Ofthesestatements a)2and3arecorrect b)1and2arecorrect c)1and3arecorrect d)1,2and3arecorrect Ans:c 46.ThemortarsusedformasonryconstructionareclassifiedbasedonstrengthinIS2250andIS1905 according totheirdesignationsL1,L2,H1,H2,M,M2. Thecorrectsequenceofincreasingorder oftheirstrengthsis

a)LLLZ.HLHI.MLMJ b)L2,L,,M2>Mi,H2)H, c)M,,M2,H,,H2,Li,L2 d)L2,L,,M,,M2,H,,H2 Ans:b 47.DirectloadcarryingcapacityofabrickmasonrywallstandingfreelyasagainstwhenitsupportsRCslab willbe a)more b)less c)thesameinboththecases d)100% Ans:b 51.A200mmthickwallmadeofmodularbricksis5mlongbetweencrosswallsand3.8mclearheight betweenRCCslabsattopandbottom.Theslendernessratioofthewallis a)15 b)19 c)20 d)25 Ans:a 52.A200mmthickbrickmasonrywallmadeofmodularbrickscarriesanaxialloadof30kN/mfromwall aboveandaneccentricloadof20kN/mfromRCCflooractingatadistanceof47.5mmfromthecentreline ofthewall.Theresultanteccentricityratiois a)b)c)d) 0.090 0.095 0.100 0.105 Ans:c 53.Thebasicstressinmasonryunitshavingheighttowidthratioof1.5maybeincreasedbyafactorof a)1.2 b)1.4 c)1.6 d)2.0 Ans:c 54.AssertionA:Foridenticalstrength,acompositecementlimemortarispreferredovercementmortar. ReasonR:Compositecementlimemortarhashigherdryingshrinkagethancementmortar. Selectyouranswerbasedonthecodesgivenbelow.Codes: a)BothAandRaretrueandRisthecorrectexplanationofA. b)BothAandRaretruebutRisnotacorrectexplanationofA. c)AistruebutRisfalse.

d)AisfalsebutRistrue. Ans:c 55.Considerthefollowingstatements: 1.Masonryinrichcementmortarthoughhavinggoodstrengthwithhighshrinkageismuchliableforsurface cracks. 2.Limemortarpossessespoorworkabilityandpoorwaterretentivityandalsosuffershighshrinkage. 3.Masonryinlimemortarhasbetterresistanceagainstrainpenetrationandislessliabletocrackwhen comparedtomasonryincementmortar. Whichofthesestatementsarecorrect? a)1,2and3 b)1and2 c)2and3 d)1and3 Ans:d 56.Formasonrybuiltin1:1:6cementlimesandmixmortarorequivalent,thehorizontalshearstress permissibleontheareaofamortarbedjointis a)0.15MPa b)0.125MPa c)0.1MPa d)0.075MPa Ans:a...