附 录
Building construction concrete crack of
prevention and processing
In the concrete engineering the familiar crack and the prevention
(1)Stem Suo crack and prevention香皂洗脸
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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 mor
e 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 durable 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 r
atio 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 appropriate 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
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 constringency, 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,
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房屋风水布局图解>什么是子网掩码 Main prevention measure:One is choo to u stem the Suo value smaller higher Huo sour salt of the earlier period strength or common the Huo sour brine mire.Two is strict the control water ash ratio, the Chan add to efficiently reduce water to increment the collap of concrete fall a degree and with easy, decrea cement and water of dosage.Three is to sprinkle before building concrete, water basic level and template even to soak through.Four is in time to overlay the perhaps damp grass mat of the plastics thin
o2o模式成功案例film, hemp slice etc., keep concrete eventually before the Ning surface is moist, perhaps spray to protect etc. to carry on protect in the concrete surface.Five is in the heat and strong wind the weather to want to establish to hide sun and block breeze facilities, protect in time.持之以恒近义词>雨人观后感
(3)Sink to sink crack and prevention
The creation which sink to sink crack is becau of the structure foundation soil quality not and evenly, loo soft or return to fill soil dishonest or soak in water but result in the asymmetry sink to decline with the result that;Perhaps becau of template just degree shortage, the template propped up to once be apart from big or prop up bottom loo move etc. to cau, especially at winter, the template prop up at jelly soil up, jelly the soil turn jelly empress creation asymmetry to sink to decline and cau concrete structure creation crack.This kind crack many is deep enter or pierce through x crack, it alignment have something to do with sinking to sink a circumstance, general follow with ground perpendicular or prent 30 °s-45 ° Cape direction development, bigger sink to si
nk crack, usually have certain of wrong, crack width usually with sink to decline quantity direct proportion relation.Crack width under the influence of temperature variety smaller.The foundation after transform stability sink to sink crack also basic tend in stability.
