In engineering construction process, problem of concrete occurrence quality, common flaw unavoidable. To concrete project, appear different quality blemish, have different processing technique and precautionary measures. Want to add an attention more in construction process only, can avoid these problems to happen or prevent these problems to appear ahead of schedule, concrete quality common fault and measure of prevention and cure introduce in detail for everybody below.
Interstitial
Interstitial phenomenon
Concrete surface appears the fine interstitial fine break of shape of meshy, chap, those who affect a building is beautiful, time grows, break is blown pluvial corrode by wind, continue very easily to deepen, affect the wear of concrete finally.
1, generation reason
1. plasticity shrinkage crack
Concrete just coagulates eventually and intensity very hour, suffer the effect of high temperature or bigger wind-force, the surface has dehydrated fast, make concrete bulk contracts quickly, strength is overwhelming its itself is contractive, because this produces chap.
2. sedimentations shrinkage crack
The structure is inhomogenous sedimentation be caused by, be in especially winter, pattern plate is propped up go up in frozen earth, the generation after frozen earth changes aspic is inhomogenous sedimentation, cause concrete structure to produce break.
3. temperature is interstitial
Coagulation person volume is larger, much to hydrate heat sends out not easily temperature rises quickly, and the surface comes loose heat is faster, the heat of bigger difference in temperature that forms inside and outside bilges cold the level that shrink is different, the surface produces the surface to be able to produce break.
2, measure of prevention and cure
1. chooses to hydrate to heat up low cement, be not active aggregate, choose grading the aggregate of arenaceous, stone with admirable, low clay content.
2. cardinal principle accumulates concrete construction to use reasonable and statified, cent piece, cent to seam measure.
3. science cooperates to compare certainly, mingle the agent that decrease water, control cement dosage, reduce to hydrate to heat up.
4. is irrigated when building, strengthen brace up pound, raise packing, can use 2 times brace up pound.
5. is wiped in time press the face, strengthen conserve, extend conserve time appropriately.
6. arranges reasonable form removal time and order.
Hemp face
Hemp face phenomenon
Hemp face phenomenon: Concrete is local the surface appears lack oar and feature of a lot of small indentation, hemp, form rough surface, but appear without reinforcing steel bar phenomenon.
1, generation reason
Surface of 1. pattern plate coarse or conglutinate grout broken bits sundry did not clear clean, surface of the concrete when form removal is stuck bad;
2. pattern plate did not besmear brush agent of drawing of patterns or agent of drawing of patterns is insufficient, the moisture of concrete of component part surface is sucked, make concrete has dehydrated face of much occurrence hemp;
Flat-fell seam of 3. pattern plate is lax, local leakage oar;
Besmear brushs separator of 4. pattern plate not divide evenly, or local leakage is brushed or invalidation. Concrete surface and pattern plate felt create hemp area;
5. pattern plate is expressed brace up pound disloyal bleb not eduction, stop in pattern plate surface to form hemp place.
2, measure of prevention and cure
Surface of 1. pattern plate clears clean, must not stick mortar of dry rigid cement waits sundry, irrigate aperture of the pattern plate before building concrete to use double-faced gum. Be bored with child wait severe, pattern plate interleaving agent should choose lasting effect, besmear is brushed even, do not get leakage to brush.
Layer of 2. concrete part of one's job is even brace up pound close-grained, to eliminate bleb till;
3. surface does not have plaster, should water in hemp side position sufficient and wet hind, cooperate to compare with former concrete go cobble mortar, wipe hemp face smooth press light.
Edge damage drops horn
Edge damage drops horny phenomenon
Structure or concrete of part of part of component part edge are local drop, irregular, edges and corners has drawback.
1, generation reason
Construction of 1. low temperature demolishs flank blame prematurely to bearing pattern plate;
When 2. form removal, edge horn gets outside force or the clog is bumped, or protection is bad, edges and corners is touched;
3. pattern plate did not besmear brush agent of drawing of patterns, or besmear is brushed not all.
2, measure of prevention and cure
1. wood pattern plate is being irrigated before building concrete, answer sufficient and wet, concrete is irrigated conserve should water seriously after building, demolish flank blame to bearing when pattern plate, concrete should have strength of above of 1.2N ／ Mm2;
The attention when 2. form removal protects edges and corners, avoid to had exerted oneself to do sth. fierce previous;
3. swing pattern plate, prevent to bump edges and corners, when carrying, it is good that finished product this world horn uses the protection such as careless bag, lest touch caustic.
4. edge damage drops horn, but the place inattentive grain authentic is divided, rinse sufficient and wet hind, inspect damaged degree with 1: 2 or 1: 2.5 cement mortar wipes filling neat, or raise a model to use taller than before one class concrete is pounded solid had filled, serious conserve.
Beehive
Beehive phenomenon
Beehive phenomenon: Concrete structure is local appear little, cobble forms crisp pine, mortar between much, cobble cavity of interstitial and similar alveolate.
1, generation reason
1. concrete cooperates to compare material of undeserved or arenaceous, stone, cement to add water the quantity is metric forbid, cause mortar little, cobble is much;
2.Concrete agitate time is insufficient, did not mix close even, workability is poor, brace up pound not close-grained;
Expect undeserved or next makings are exorbitant below 3. , did not set string of canister to make cobble is centered, cause cobble mortar separation;
4.Concrete is not statified next makings, brace up pound disloyal, leakage brace up or brace up beat time insufficient;
5.Pattern plate aperture was not blocked up severe, grout prediction of a person's luck in a given year;
6.Reinforcing steel bar is closer, use cobble bead means passes big or slump is too small;
7.Ministry of root of body of foundation, column, wall did not continue by fits slightly fill superstratum concrete.
2, measure of prevention and cure
1, basis designs the requirement of the file, strict control concrete cooperates to compare, often check, accomplish metric and accurate, concrete mixes close even, slump suits, height of the makings below concrete has exceeded 2m to should set string of canister or chute, irrigate the makings below layer of part of one's job, statified brace up pound, prevent to leak brace up.
2, pattern plate is seamed should jam close, in irrigating, answer to check pattern plate to prop up a circumstance to prevent leakage oar at any time, ministry of root of wall of foundation, column, thin wall, costal region board should cast intermittent period of time in bottom, upside concrete is irrigated again after heavy fact, avoid " of occurrence " sodden neck.
3, processing of little a honeycomb-like thing: After Tong surface rinse is clean, with 1: 2 or 1: 2.5 cement mortar wipes smooth squeezing ramming; Bigger a honeycomb-like thing, authentic goes to beehive place fragile and inattentive grain, after scrub is clean, raise a model to use tall careful ram pounds concrete of one class fine stone solid.
Dew muscle
Show muscle phenomenon
Show muscle phenomenon: Concrete is in-house advocate muscle, deputy muscle or band muscle are local and bare in surface of structural component part.
1, generation reason
When 1. fill builds concrete, displacement of space block of covering layer of reinforcing steel bar or space block too little or leakage is put, cause reinforcing steel bar clingy pattern plate appears;
2. construction component part is sectional small, reinforcing steel bar is too close, cobble card is on reinforcing steel bar, make cement mortar cannot fill reinforcing steel bar all round, cause dew veins that stand out under the skin;
3. concrete cooperates to compare undeserved, generation leaves fold, template place is short of oar or oar of pattern plate leakage.
4. concrete covering layer too small or covering layer is in concrete brace up pound disloyal;
5. or brace up dolly bumps reinforcing steel bar or trample reinforcing steel bar, make displacement of reinforcing steel bar, cause dew veins that stand out under the skin;
6. pattern plate is not lubricant. Bibulous felt or drawing of patterns are premature, the edge damage when form removal, drop horn, cause leakage veins that stand out under the skin.
2, measure of prevention and cure
1, irrigate build concrete, should make sure position of reinforcing steel bar and covering layer ply are correct, strengthen examine examine, when reinforcing steel bar is concentrated, should choose the cobble of proper bead diameter, make sure concrete cooperates to compare accurate with good workability;
2, irrigate height exceeds 2m, application strings together a canister, or chute undertakes falling expecting, in order to prevent separation; Pattern plate should sufficient and wet block good aperture up seriously;
3. concrete brace up pound forbidden bump reinforcing steel bar, when the operation, avoid trample reinforcing steel bar, if have,take off buckle wait to be adjusted in time straight;
Concrete of 4. covering layer wants brace up pound close-grained;
5. masters time of drawing of patterns correctly, prevent premature form removal, touch bad edges and corners;
Muscle of 6. surface leakage, after scrub is clean, wipe in the surface 1: 2 or 1: 2.5 cement mortar, allow place of full leakage muscle is wiped smooth;
The authentic with 7. leakage deeper muscle goes fragile concrete and outstanding grain, after rinse is clean, with taller than before the squeezing ramming of ram of fine stone concrete of one class.
Hole
Hole phenomenon
Hole phenomenon: Concrete structure interior has the space with larger size, local particularly big without concrete or beehive, local or reinforcing steel bar is all bare.
1, generation reason
1. is in closer place or obligate hole mix reinforcing steel bar to bury a part beforehand, the makings below concrete is lain between, not brace up pound continue to irrigate build superstratum concrete;
The separation on 2. coagulation, mortar is detached, cobble forms a pile, run badly oar, did not undertake again brace up pound.
3. concrete falls makings is overmuch, heavy panel, next makings are exorbitant, vibrator vibration does not arrive, form inattentive hole;
Drop inside 4. concrete, block, mud piece sundry, concrete is stayed in by card.
2, measure of prevention and cure
1. is in thick and fast in reinforcing steel bar reach complex place, use fine stone concrete to irrigate build, be full of inside pattern plate, serious and statified brace up pound close-grained, take strict precautions against leakage brace up, arenaceous Shi Zhonghun has tool of argillaceous piece, pattern plate to wait sundry drop the tract that mix doubt inside, answer to keep clear of in time clean;
The inattentive concrete all round 2. general hole and weak chorion authentic are divided, rinse with pressure water, wet hind with high strenth grade fine stone concrete is irrigated carefully build, pound solid.
Bilge model
Bilge modular phenomenon
Irrigating when building, because pattern plate is raised,may set, colligation of reinforcing steel bar, concrete vesicant, irrigate build height exorbitant bring about irrigate build pressure to wait for a reason greatly, bring about whole pattern plate to be out of shape, piece (go up) , the flow that concrete runs is large.
1, generation reason
Respect of 1. pattern plate
Pattern plate problem, include quality of pattern plate itself poor, intensity is insufficient or pattern plate material is qualitative choose undeserved etc. Pattern plate supports an issue, include to prop up the not firm, check the number that prop up to measure the insufficient, means that prop up to choose undeserved etc. Problem of pattern plate join, include undeserved to pulling join bolt amount and span etc.
2. uses work staff issue
The member that include construction person operates undeserved, operation not strong, technology closes heart of not serious, responsibility nevertheless etc.
3. runs a side
Management does not reach the designated position, constituent not do one's best, system and measure are not full, executive examination is insufficient. Administrator is irrigated to old standard concrete build board medium detail is not familiar, cooperate between team and group not tacit etc.
2, measure of prevention and cure
When 1. beat concrete, ask to expect below even semmetry, strict control irrigates height, especially pattern plate of mouth of door an opening in a wall two side, should assure concrete already brace up pound close-grained, it is beyond the mark to should prevent again brace up pound cause pattern plate to be out of shape.
When 2. uses construction of wooden pattern plate, plywood pattern plate, after checking and accept qualification, want to be irrigated in time build, prevent insolate drench happening is out of shape. Repeat use wooden pattern plate must close check rehabilitate.
3. asks strictly to operate personnel to control good concrete brace up pounded insertion deepness, must not pass deep. Already brace up pounded place must not insert vibration to hold in both hands again brace up pound, avoid to explode modular phenomenon arises.
