Building construction concrete crack of
prevention and processing
Abstract
The crack problem of concrete is a widespread existence but again difficult in solve of engineering actual problem， this text carried on a study analysis to a little bit familiar crack problem in the concrete engineering, and aim at concrete the circumstance put forward some prevention, processing measure.
Keyword：Concrete crack prevention processing
Forewordmylf
Concrete's ising 1 kind is anticipate by the freestone bone， cement， water and other mixture but formation of the in addition material of quality brittleness not and all material.Becau the concrete construction transform with onelf， control etc。 a ries maneater
problem, harden model of in the concrete existence numerous tiny hole， spirit cave and tiny crack， is exactly becau the beginning start blemish of existence just make the concrete prent one some not and all the characteristic of quality.The tiny crack is a kind of harmless crack and accept concrete heavy, defend Shen and a little bit other u function not a creation to endanger.But after the concrete be subjected to lotus carry, difference in temperature etc。 function, tiny crack would continuously of expand with connect, end formation we can e without the aid of instruments of macro view the crack be also the crack that the concrete often say in the engineering。
Concrete building and Gou piece usually all take wer to make of， becau of crack of existence and development usually make inner part of reinforcing bar etc. material creation decay, lower reinforced concrete material of loading ability， durable and anti- Shen ability， influence building of external appearance， rvice life, verity will threat arrive people's life and property safety。A lot of all of crash of engineerings is becau of the unsteady development of the crack with the result that.Modern age science rearch with a great deal of of the concrete engineering practice certificate, in the concrete engine
ering crack problem is ineluctable， also acceptable in certainly of the scope just need to adopt valid of measure will it endanger degree control at certain of scope inside。The reinforced concrete norm is also explicit provision：Some structure at place of dissimilarity under the condition allow existence certain the crack of width.But at under construction should as far as possible adopt a valid measure control crack creation， make the structure don’t appear crack possibly or as far as possible decrea crack of amount and width, particularly want to as far as possible avoid harmful crack of emergence， insure engineering quality thus.
Concrete crack creation of the reason be a lot of and have already transformed to cau of crack:Such as temperature variety, constringency, inflation, the asymmetry sink to sink etc。 reason cau of crack;Have outside carry the crack that the function cau;Protected environment not appropriate the crack etc。 caud with chemical effect.Want differentiation to treat in the actual engineering, work°out a problem according to the actual circumstance。
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In the concrete engineering the familiar crack and the preventionchita
1。Stem Suo crack and prevention
Stem the Suo crack much appear after the concrete protect be over of a period of time or concrete sprinkle to build to complete behind of around a week.In the cement syrup humidity of evaporate would creation stem Suo, and this kind of constringency is can't negative。Stem Suo crack of the creation be main is becau of concrete inside outside humidity evaporate degree dissimilarity but cau to transform dissimilarity of result：The concrete is subjected to exterior condition of influence， surface humidity loss lead quick， transform bigger， inner part degree of humidity variety smaller transform smaller, bigger surface stem the Suo transform to be subjected to concrete inner part control， creation more big pull should dint but creation crack。The relative humidity is more low, cement syrup body stem Suo more big, stem the Suo crack be more easy creation.Stem the Suo crack is much surface parallel lines form or the net shallow thin crack, width many between 0.05-0。2 mm， the flat surface part much e in the big physical volume concrete and follow it more in thinner beam plank short to distribute.Stem Suo crack usually the anti— Shen of influence concrete， cau the duraheir是什么意思
ble of the rust eclip influence concrete of reinforcing bar， under the function of the water pressure dint would creation the water power split crack influence concrete of loading dint etc.。Concrete stem the Suo be main with water ash of the concrete ratio， the dosage of the composition， cement of cement， gather to anticipate of the dosage of the property and dosage， in addition etc。 relevant。
Main prevention measure:While being to choo to u the constringency quantity smaller cement， general low hot water mire and powder ash from stove cement in the adoption, lower the dosage of cement.Two is a concrete of stem the Suo be subjected to water ash ratio of influence more big, water ash ratio more big, stem Suo more big, so in the concrete match the ratio the design should as far as possible control good water ash ratio of choo to u， the Chan add in the meantime accommodation of reduce water。Three is strict control concrete mix blend with under construction of match ratio， u of concrete water quantity absolute can't big in match ratio design give ttle of u water quantity。Four is the earlier period which strengthen concrete to protect， and appropriate extension protect of concrete time。Winter construction want to be appropriat
nsation什么意思e extension concrete heat prervation to overlay time， and Tu2 Shua protect to protect.Five is a constitution the accommodation is in the concrete structure of the constringency w.
2。The Su constringency crack and prevention水獭英语
2013年6月四级作文 Su constringency is the concrete is before conden, surface becau of lo water quicker but creation of constringency.The Su constringency crack is general at dry heat or strong wind the weather appear, crack’s much prenting in the center breadth， both ends be in the centerthin and the length be different， with each other not coherent appearance。Shorter crack general long 20—30 cm， the longer crack can reach to a 2-3 m, breadth 1—5 mm。It creation of main reason is：The concrete is eventually almost having no strength or strength before the Ning very small， perhaps concrete just eventually Ning but strength very hour, be subjected to heat or compare strong wind dint of influence, the concrete surface lo water to lead quick， result in in the capillary creation bigger negative press but make a concrete physical volume sharply constringenc
y， but at this time the strength of concrete again can’t resist its constringency, therefore creation cracked。The influence concrete Su constringency open the main factor of crack to have water ash ratio， concrete of conden time， environment temperature, wind velocity, 。.
