Prestressed concrete

Simintin da aka riga aka rigaya wani nau'i ne na siminti da ake amfani da shi wajen gini. Yana da matuƙar “matsewa” (matsi) yayin samarwa, ta hanyar da ke ƙarfafa ta daga rundunonin ƙarfi waɗanda za su wanzu lokacin da ake hidima. [4]

Ana samar da wannan matsawa ta hanyar tashin hankali na "tendons" masu ƙarfi da ke cikin ko kusa da simintin kuma ana yin shi don inganta aikin simintin a cikin sabis.[5] Tendon na iya ƙunshi guda ɗaya

Pre-tensioned kankare adadi uku; Dutsen kore mai duhu an riga an ɗaure shi a cikin gadon simintin simintin koren haske Pre-tensioning tsari Pre-tensioned kankare shine bambance-bambancen simintin da aka ɗora inda ginshiƙan ke daɗaɗawa kafin a jefa simintin.[1]: 25  Ƙunƙarar ƙugiya ga tendons yayin da yake warkewa, bayan haka an saki ƙarshen jijiyoyi, kuma Ana tura dakarun tashin hankali na jijiyoyi zuwa siminti azaman matsawa ta hanyar juzu'i.[6]: 7  Form don kankare I-beam tare da tendons a ƙananan yanki Rigar gada da aka rigaya ta dawwama a cikin gadon da aka rigaya, tare da tendons masu igiya guda ɗaya suna fita ta hanyar tsarin aiki. Pre-tensioning dabara ce ta gama gari, inda aka kera simintin siminti a waje daga wurin tsari na ƙarshe kuma a kai shi zuwa wurin da zarar an warke. Yana buƙatar ƙaƙƙarfan, tsayayyun wuraren ƙulla ƙarshen ƙugiya waɗanda ke shimfiɗa jijiyoyi. Waɗannan ƙusoshin sun zama ƙarshen “gado na simintin gyare-gyare” wanda ƙila ya ninka tsawon simintin simintin da ake ƙirƙira sau da yawa. Wannan yana ba da damar gina abubuwa da yawa daga ƙarshe zuwa ƙarshe a cikin aikin farko na tashin hankali, yana ba da damar fa'idodin yawan aiki da ƙimar sikelin tattalin arziƙi.[6][8]

 Adadin haɗin 
(ko mannewa) da za'a iya samu tsakanin simintin da aka saita da kuma saman jijiyoyi yana da mahimmanci ga tsarin da aka rigaya ya taso, saboda yana ƙayyade lokacin da za'a iya sakin ɗigon jijiyoyi lafiya. Ƙarfin haɗin gwiwa a farkon shekarun kankare zai hanzarta samarwa kuma ya ba da damar ƙirƙira tattalin arziƙi. Don haɓaka wannan, tendons da aka rigaya sun kasance yawanci sun ƙunshi keɓaɓɓun wayoyi ko igiyoyi, waɗanda ke ba da mafi girman yanki don haɗawa fiye da jijiyoyi masu ɗaure.[6] Crane yana sarrafa katakon kankare Pre-tensioned, precast hollow-core slab ana sanyawa Ba kamar na simintin da aka yi bayan tashin hankali ba (duba ƙasa), jijiyoyi na abubuwan simintin da aka riga aka girka gabaɗaya suna samar da madaidaiciyar layi tsakanin ƙarshen anchorages. Inda ake buƙatar tendons "profied" ko "harped" [9], ɗaya ko fiye na tsaka-tsaki suna samuwa a tsakanin iyakar tendon don riƙe tendon zuwa daidaitattun layin da ake so yayin tashin hankali.[1]: 68-73  [ 6]: 11  Irin waɗannan ɓangarorin yawanci suna yin aiki da ƙarfi sosai, don haka suna buƙatar ingantaccen tsarin tushen gado. Ana amfani da jijiyoyi madaidaici a cikin abubuwan da aka siffata na siminti na “daidaitacce”, kamar su shuɗi mara zurfi, ƙwanƙwasa-ƙasa; alhãli kuwa an fi samun jijiyoyi masu ƙirƙira a cikin gada mai zurfi da gada mai zurfi. An fi amfani da simintin da aka riga aka yi tashe-tashen hankula don kera ginshiƙan gine-gine, ginshiƙan bene, ƙwanƙwasa-ƙasa, baranda, lintels, tulin tuƙi, tankunan ruwa da bututun siminti.

 Manazarta 

 ^ Jump up to:a b c d e f g h i j 
 ^ Jump up to:a b c d e f g 
 ^  Post-tensioned concreted is "structural concrete in which internal stresses have been introduced to reduce potential tensile stresses in the concrete resulting from loads."