Thawj zaug, tib neeg pib tham txog pob zeb nyob rau ntau pua xyoo dhau los. Txawm li cas los xij, nyob rau lub sijhawm no, cov khoom siv no, zoo li lwm yam khoom siv hauv tsev, tau dhau los ntawm kev hloov pauv mus ntev.
Thawj thawj pob zeb tau pom los ntawm archaeologists ntawm ntug dej ntawm Danube hauv Yugoslavia hauv 5600 BC. Lub sijhawm ntawd, cov khoom siv hauv tsev no yog ua los ntawm pob zeb thiab cov txiv qaub liab hauv zos.
Hnub no, pob zeb yuav tsum nkag siab tias yog cov khoom siv pob zeb ntawm cov khoom siv dag zog, uas yog tsim los ntawm kev sib xyaw kom zoo sib xyaw nrog dej, nrog rau cov khoom loj thiab me me, uas tau muab coj los ua raws li kev faib ua feem.
Lub zog ntawm pob zeb
Tus yam ntxwv tseem ceeb ntawm pob zeb yog nws lub zog. Lub zog ntawm pob zeb yog nyob ntawm ntau yam. Cov txheej txheem hydration nws tus kheej muaj ob theem:
- Nyob. Cov theem no kav txog ib hnub. Ntau nyob ntawm qhov kub ntawm no. Yog li, piv txwv li, ntawm qhov kub ntawm ntau tshaj 20 degrees, pob zeb yuav siv sij hawm peb teev los teeb. Yog tias qhov kub thiab txias yog xoom, theem no yuav kav li 15-20 teev.
- Ntxhais. Cov theem no pib tam sim tom qab qhov dhau los.kev nqis tes ua thiab kav ntev ntau xyoo.
Txawm li cas los xij, nws yuav tsum tau muab sau tseg tias kev kho cov pob zeb ua haujlwm tsuas yog muaj dej noo. Lub zog ntawm pob zeb thiab cov qauv nws tus kheej tag nrho nce vim kev sib cuam tshuam ntawm cov khoom no nrog dej.
Nws tseem yuav tsum tau coj mus rau hauv tus account qhov tseeb tias qhov kev kho ntawm cov pob zeb ua haujlwm nres ob qho tib si hauv huab cua kub thiab txias. Yog li ntawd, nyob rau hauv qhov kub thiab txias, freshly poured qhob yog pom zoo kom npog nrog ib tug damp burlap los tiv thaiv dej evaporation. Qhov ntsuas kub tsis zoo ua rau cov dej khov, uas yog ib feem ntawm cov pob zeb sib tov. Nyob rau hauv cov ntaub ntawv ntawm qhov zoo kub, cov txheej txheem hydration txuas ntxiv, txawm li cas los xij, los ntawm lub sij hawm no cov yam ntxwv ntawm cov qauv no deteriorating, nrog rau lub zog ntawm pob zeb. Vim li no, cov kws tshaj lij pom zoo kom ntxiv cov khoom tshwj xeeb thaum lub sij hawm npaj cov kev daws teeb meem.
chav kawm muaj zog
Cov ntsuas tseem ceeb ntawm cov pob zeb muaj xws li:
- Qhob lub zog hauv cov ntaub ntawv ntawm axial compression.
- Qhob muaj zog chav kawm nyob rau hauv rooj plaub ntawm axial nro.
Muaj ntau chav kawm ntawm kev sib xyaw ua ke, cov ntsiab lus tseem ceeb yog:
- Hom kev daws teeb meem nyob ntawm Frost resistance. Qhov sib tov no yog siv rau hauv kev tsim kho cov qauv uas raug hloov pauv khov thiab thaw.
- Qib ntawm kev daws teeb meem nyob ntawmwaterproof. Qhov kev sib xyaw no yog siv rau hauv kev tsim kho ntawm cov chaw nres tsheb fais fab, pas dej, cov kwj dej thiab lwm yam.
siv pob zeb
Raws li cov kev ntsuas kev lag luam thiab kev lag luam, rau kev tsim kho ntawm txhua tus qauv, kev xaiv ntawm cov chav kawm xav tau thiab hom kev sib xyaw ua ke yog ua los ntawm tus kheej. Lub zog ntawm pob zeb hauv qhov no plays lub luag haujlwm tseem ceeb. Cov kws tshaj lij pom zoo kom siv cov pob zeb tsawg kawg ntawm B-15 chav kawm rau cov pob zeb ua kom muaj zog compressed pas nrig hom. Rau arches thiab kab, nws yog qhov zoo tshaj plaws los siv B-20-B-30 chav ua vaj tse. Rau pem teb slabs thiab kab teeb, chav B-15 pob zeb yog tsim.
