淺談施工縫的處理(土木工程畢業(yè)設(shè)計(jì)英文翻譯)

1、 Shallowly discusses the construction joint processingIntroduction Massive engineering structure shakes harms the example to indicate that, the portal frame construction pitch point universal destruction is heavier, often causes the structure to expire, the Chinese and foreign scholar analyzes indic

2、ated, this is the various reason, including the design fault, has not strengthened the pitch point intensity, realizes reason and so on strong pitch point strong anchor. Simultaneously constructs also has the construction quality weakness, difficulty with guarantees the design anticipated target. In

3、 construction new old concrete construction gap time, continues the surface position, continues the surface processing method, the new old coagulation locally born ripe ingredient and inspires pounds the influence pitch point caking intensity which the control quality all makes, therefore in portal

4、frame construction project construction process, because in each pillar construction inevitably and the lower level pillar existence construction joint, how does leave alone the construction joint, how processes the construction joint, causes the project quality not to receive affects, guaranteed co

5、ncrete the structure security, appears especially importantly.1.current portal frame construction pitch point job practice and the flaw. (1) the early time in the general portal frame construction, after pours a pillar, carries on a mold, after the template installment completes only then enters sew

6、er the working procedure to pour the upper formation girder concrete, therefore acts according to constructs the time limit for a project and the person, the material, machine and so on the situation, the new old concrete continues the gap time length not one, when pouring the general pitch point po

7、urs together along with the girder concrete, and the pitch point concrete intensity rank carries on the construction according to girder (2) along with the scientific research development and the construction level enhancement, in particular specialized level higher big general contractor starts in

8、view of steel construction the pitch point construction quality weak characteristic to take a series of measures, when pours the upper oration steel construction carries on chiseling processing with the drill rod front, pours carries on the watering to the old concrete to be moist, and in hands over

9、 in the composition plane with the high-grade cement mortar shop, steel construction the pitch point area concrete intensity rank generally uses the pillar (common pillar intensity and so on to rise), is pouring the pitch point zone time to strengthen inspires pounds and the strict control water-to-

10、cement ratio. After a series of processing measure, the construction quality obtained the enhancement, but column the pitch point area concrete still was the construction weak area, is very difficult to obtain ideally continues the effect. (3) although continued the spot to carry on processing, but

11、its flaw was very obvious: First uses the drill rod to carry on chiseling processing, extremely shirt and old concrete, so that the old concrete produces the initial micro crack, seriously affects the new old concrete to continue the intensity, also chiseling processing difficulty with controls the

12、processing quality specification front, pours to continues the spot moistly to carry on the watering to be very easy to work just the opposite, thus increased has handed over the composition plane place concrete water-to-cement ratio, but in handed over in the composition plane with the high-grade c

13、ement mortar shop to be very easy because the high-grade cement mortar and the green concrete hydro mass congealed and the contraction different, thus caused to continue the surface to be easier to have the initial stress and the initial micro crack. But pitch point area concrete intensity rank diff

14、erence and girder, thus caused the column girder pitch point area actually to produce four frontal zones (although girder and pitch point area whole poured, but concrete intensity rank general different, thus also has created weak contact surface), when construction was very difficult to control ins

15、pires pounds the density and the time, was very easy because inspired pounds the depth but to injury and the old concrete, or because strengthened inspires pounds causes originally water-to-cement ratio to have the partial bleeding phenomenon on the quite small concrete, thus the influence concrete

16、intensity growth, reduced the contact surface caking intensity.2.Column pitch points areas destruction mechanism and the earthquake resistance design request by shakes harms the investigation obviously, column the pitch point area destruction, mostly is because the pitch point area does not have sti

17、rrup or are few stirrup, in cuts presses under the function the concrete to appear the slanting crack even to extrude destroys, creates the longitudinal reinforcement buckling to become the lantern shape. Therefore, guaranteed the pitch point area not premature has the shearing failure main measure

18、is guaranteed the pitch point area concrete the intensity and the density, is enough in the pitch point area disposition stirrup. The design column frequently uses the different rank the concrete, when the construction must pay attention to column the pitch point spot concrete rank to be supposed sa

19、me or is slightly low with the column concrete rank (difference not to be able to surpass 5M pa). Thus realizes the strong pitch point strong anchor. In the vertical pressure and the girder end pillar end moment, under the shearing force function, the pitch point area has the more complex stress con

20、dition. Pitch point experiment which from unit and so on Beijing construction design institute carries on obviously, the pitch point destruction process approximately may divide into two stages: The first stage for passes the crack stage. When the function and the core shearing force achieved when 6

21、0 70%, the core area appears links up the slanting crack, the crack opening approximately is 0.1 0.2m m, the reinforcement stress is very small (does not surpass 20M pa), this stage shearing force mainly undertakes by the concrete. The second stage for bursts the stage. Gradually enlarges along with

22、 repeatedly the load, links up the crack to widen, the shearing force mainly undertakes by the concrete, stirrup achieves one after another submits, crowds garrulously in the concrete front achieves the biggest bearing capacity. When design takes the limiting condition by the second stage.3.standard

23、s leave alone and the processing request to the construction. Joint for enable the concrete structure to have a better integrity; the concrete pour should continuously carry on. If because technical or organizations reason cannot continuously carry on pours, also the middle idle time has the possibi

24、lity to surpass the concrete initially to congeal, then should in front of concrete placement determine remains in the appropriate position supposes the construction joint. The construction joint was refers first irrigates the concrete to congeal the hardening, then continued the placing concrete ju

25、nction plane between the new old concrete, it was the structure weak spot, thus suitably kept the structure to be smaller the shearing force also to be advantageous for the construction spot. The column should keep the water flush joint, the girder wooden fence should remain vertical joints. When st

26、arts from the construction joint place continue the concrete, after must wait the concrete compressive strength which constructs to achieve 1.2N /m2. can carry on, moreover must make some processing to the construction joint, strengthens the new old concrete the connection, reduces the construction

27、joint as far as possible the adverse effect which brings to the structure integrity. The treating processes are: First in hardened on the concrete surface, eliminates the cement thin film and the loose gravel as well as the weak layer of concrete, and performs fully moist, the flushing is clean, als

28、o does not have to remain has the pending; Then first spreads cement mortar in front of the concrete in the construction joint place or and in the concrete the ingredient same cement mortar; When concrete, must carefully inspire pounds densely, causes the new old concrete union to be close.4.accordi

29、ng to the scientific research achievement union actual construction proposed the improvement construction joint processing method and the theory basis. (1) First massively test indicated continues the surface to carry on the rough treatment to be allowed obviously to enhance continues the surface ca

30、king intensity, but roughness enhances after the certain degree, continues the surface caking intensity the enhancement no longer to be obvious. With ordinary chiseling method existence obvious flaw, but uses the high-pressured water spray treatment to be allowed to obtain a better rough contact sur

31、face, and does not injury and the old concrete, but high-pressured water equipment construction cost expensive, technical content high, looked in the present stage from our country actual construction technology and the construction level, the application high pressure water treatment less quantitie

32、s construction joint not too is actual. Therefore myself proposed in the pouring note under story post period of time from 11 p.m. to 1 a.m, after waits at the beginning of the concrete to congeal causes on the pillar with the artificial method the surface to present the zigzag, according to the con

33、crete thick aggregate particle size (generally is 2 4cm), the dentil depth for sticks the surface old concrete maximum aggregate particle size 1/4 1/2; grooving the mean breadth for sticks the surface old concrete maximum aggregate particle size 1 1.5 times. This law biggest merit is advantageous fo

34、r the control construction quality, causes to stick in the surface roughness to have the good uniformity. Like these both has avoided chiseling, avoids the wound and the old concrete structure, and realized has continued the surface roughness, also was easy to control the quality specification, when

35、 continuing only used to strip the loose thick aggregate. (2) in order to reduce the pitch point area weak contact surface quantity, myself thought should separate in the pitch point area two sides girder pours (even if does not separate, because pitch point concrete intensity rank is different with

36、 the girder concrete, also can produce contact surface weak level), but the pitch point pours together with the upper formation pillar, like this enabled the pitch point area to have three to continue the surface, the pillar only has to continue the surface (to be short to continue surface), was adv

37、antageous to enhances the pillar concrete anti- to cut the ability, delayed the pillar slanting crack the appearance. Simultaneously also conforms to the earthquake resistance request strong column weak girder principle, delays time which the pillar submits. Thus causes the pitch point area same the

38、 level pillar constitution whole. (3) when leaves alone the girder construction joint should retain the diagonal 45 angle (girder under construction joint nearby pillar), like this processes the result on the one hand causes the pitch point area girder end shear not with the construction joint super

39、position, is advantageous to anti- cuts anti- pulls, delays the time which the concrete crack appears. On the other hand acts according to had the experimental study result to indicate that, on slanting makes up compared to declines makes up sticks the surface intensity high, the same principle on s

40、lanting makes up should make up the intensity the tradition job practice in side to be higher than. Finally, because the construction joint assumes 45 the angle, thus expanded the pitch point whole to pour the region, was advantageous to realizes the strong pitch point request. (4) has when the cond

41、ition may (for instance reduce medicinal preparation using the patching contact surface medicinal preparation, had experiment and theoretical analysis indicated reduces medicinal preparation to be better than plumping agent), as a result of the economy and other reasons, in the actual project constr

42、uction very little uses the contact surface medicinal preparation in the small area construction joint, present constructs from the majority looked, should consider the improvement and the control interface mortar application. According to had the experimental conclusion and the theoretical analysis

43、, myself suggested applies makes the contact surface medicinal preparation with the pillar water-to-cement ratio same element cement mortar. (5)acts according to myself many years construction experience, because the pitch point spot girder steel bar intersects through and stirrup the encryption, fa

44、ctor and so on anchor causes the pitch point spot steel bar densely, constructs with difficulty, therefore the suggestion use minor diameter vibrates the stick (for instance 50sticks) to inspire pounds the pitch point spot, like this not the easy wound and the old concrete structure, also are easy t

45、o control inspires pounds the quality, reduces as far as possible secretes the water volume, the improvement junction plane tiny view structure, is advantageous to enhancing the construction joint the caking intensity.5. conclusions and forecast This article according to tested and the theory scient

46、ific research achievement union portal frame construction concrete girder pitch point spot construction weak area carries on the discussion, key actually embarks from the present project and the full consideration is economical and the realistic factor, proposed the pitch point spot construction joi

47、nt continues processing the new method to discuss its theory basis, and already carried on the Practice in the partial projects, obtained good has continued the effect. But waits for to the massive projects practice proved its validity, simultaneously is worth further carrying on the theory and the

48、experiment analyzes. The current related scientific research mainly from macroscopic embarks to tiny view, has initially promulgated the new old concrete caking mechanism through the experiment and the theoretical analysis, myself think not only must study the new old concrete from the theory to con

49、tinue the intensity, must study from the current our country construction enterprise actual level face the project application job practice, thus applies as soon as possible the theory achievement to the practice, enhances our country to construct enterprises overall quality, guaranteed the construc

50、tion quality, better satisfies the design anticipated target.淺談施工縫的處理引言 通過大量工程結(jié)構(gòu)震害實(shí)例, 框架結(jié)構(gòu)節(jié)點(diǎn)普遍破壞較重,往往導(dǎo)致結(jié)構(gòu)失效, 中外學(xué)者分析表明, 這是多方面的原因, 包括設(shè)計(jì)失誤, 沒有加強(qiáng)節(jié)點(diǎn)強(qiáng)度, 實(shí)現(xiàn)強(qiáng)節(jié)點(diǎn)強(qiáng)錨固等原因。同時(shí)施工中也存在施工質(zhì)量弱點(diǎn), 難于保證設(shè)計(jì)預(yù)期目標(biāo)。施工中新老混凝土施工間隔期, 接續(xù)面方位, 接續(xù)面處理方法, 新老混凝土生熟配料及振搗控制質(zhì)量都密切的影響著節(jié)點(diǎn)粘結(jié)強(qiáng)度, 因此在框架結(jié)構(gòu)工程施工過程中,由于每一層柱子施工中必然與下層柱子存在施工縫,怎樣留置施工縫, 怎樣處理施

51、工縫, 使工程質(zhì)量不受影響,保證砼結(jié)構(gòu)的安全性,更顯得尤為重要。1、當(dāng)前框架結(jié)構(gòu)梁柱節(jié)點(diǎn)施工方法及缺陷(1) 早期在一般的框架結(jié)構(gòu)施工中, 澆注完一層柱子后, 進(jìn)行支模, 模板安裝完成后才進(jìn)入下道工序澆注上層梁混凝土, 因此根據(jù)施工工期及人、材、機(jī)等情況, 新老混凝土接續(xù)間隔期長(zhǎng)短不一, 在澆注時(shí)一般節(jié)點(diǎn)( 梁柱交界處) 隨梁混凝土一起澆注, 并且節(jié)點(diǎn)混凝土強(qiáng)度等級(jí)按梁進(jìn)行施工。(2) 隨著科研的發(fā)展及施工水平的提高, 尤其是專業(yè)化水平較高的大建筑公司開始針對(duì)梁柱節(jié)點(diǎn)施工質(zhì)量薄弱的特點(diǎn)采取一系列措施, 在澆注上層梁柱時(shí)用鋼釬進(jìn)行鑿毛處理, 澆注前對(duì)老混凝土進(jìn)行澆水濕潤(rùn), 并用高標(biāo)號(hào)水泥砂漿鋪在

52、交接面上, 梁柱節(jié)點(diǎn)區(qū)混凝土強(qiáng)度等級(jí)一般采用柱子( 一般柱子強(qiáng)度等級(jí)高) ,在澆注節(jié)點(diǎn)區(qū)時(shí)加強(qiáng)振搗并嚴(yán)格控制水灰比。經(jīng)過一系列處理措施后, 施工質(zhì)量得到了提高, 但梁柱節(jié)點(diǎn)區(qū)混凝土仍舊是施工薄弱區(qū), 很難取得理想的接續(xù)效果。(3) 雖然接續(xù)部位進(jìn)行了處理, 但其缺陷是很明顯的: 首先用鋼釬進(jìn)行鑿毛處理, 極易傷及老混凝土, 以致老混凝土產(chǎn)生初始微裂縫, 嚴(yán)重影響新老混凝土的接續(xù)強(qiáng)度, 且鑿毛處理難于控制處理質(zhì)量標(biāo)準(zhǔn), 澆注前對(duì)接續(xù)部位進(jìn)行澆水濕潤(rùn)很容易適得其反, 從而增大了交接面處混凝土的水灰比, 而用高標(biāo)號(hào)水泥砂漿鋪在交接面上很容易由于高標(biāo)號(hào)水泥砂漿與新混凝土漿體凝結(jié)及收縮不同, 從而使接續(xù)

53、面更容易產(chǎn)生初應(yīng)力和初始微裂縫。而節(jié)點(diǎn)區(qū)混凝土強(qiáng)度等級(jí)區(qū)別與梁, 從而使柱梁節(jié)點(diǎn)區(qū)實(shí)際產(chǎn)生了四個(gè)界面區(qū)( 雖然梁與節(jié)點(diǎn)區(qū)整體澆注, 但混凝土強(qiáng)度等級(jí)一般不同, 因而也造成了薄弱界面) , 在施工時(shí)很難控制振搗密度與時(shí)間, 很容易由于振搗過深而傷及老混凝土, 或者由于加強(qiáng)振搗而使本來(lái)水灰比就比較小的混凝土產(chǎn)生局部泌水現(xiàn)象, 從而影響混凝土強(qiáng)度的增長(zhǎng), 降低界面粘結(jié)強(qiáng)度。2、梁柱節(jié)點(diǎn)區(qū)破壞機(jī)理及抗震設(shè)計(jì)要求由震害調(diào)查可見, 梁柱節(jié)點(diǎn)區(qū)的破壞, 大都是由于節(jié)點(diǎn)區(qū)無(wú)箍筋或少箍筋, 在剪壓作用下混凝土出現(xiàn)斜裂縫甚至擠壓破壞,造成縱向鋼筋壓屈成燈籠狀。因此, 保證節(jié)點(diǎn)區(qū)不過早發(fā)生剪切破壞的主要措施是保證節(jié)

54、點(diǎn)區(qū)混凝土的強(qiáng)度及密實(shí)性, 在節(jié)點(diǎn)區(qū)配置足夠的箍筋。設(shè)計(jì)梁柱常常采用不同等級(jí)的混凝土, 施工時(shí)必須注意梁柱節(jié)點(diǎn)部位混凝土等級(jí)應(yīng)該和柱混凝土的等級(jí)相同或略低( 相差不能超過5M pa) 。從而實(shí)現(xiàn)強(qiáng)節(jié)點(diǎn)強(qiáng)錨固。在豎向壓力及梁端柱端彎矩, 剪力作用下, 節(jié)點(diǎn)區(qū)存在較復(fù)雜的應(yīng)力狀態(tài)。從北京市建筑設(shè)計(jì)院等單位進(jìn)行的節(jié)點(diǎn)實(shí)驗(yàn)可見, 節(jié)點(diǎn)的破壞過程大致可分為二個(gè)階段: 第一階段為通裂階段。當(dāng)作用與核心的剪力達(dá)到6070% 時(shí), 核心區(qū)出現(xiàn)貫通斜裂縫, 裂縫寬度約為0.10.2m m ,鋼筋應(yīng)力很小( 不超過20M pa) ,這個(gè)階段剪力主要由混凝土承擔(dān)。第二階段為破裂階段。隨著反復(fù)荷載逐漸加大, 貫通裂縫加寬, 剪力主要由混凝土承擔(dān), 箍筋陸續(xù)達(dá)到屈服,在混凝土擠碎前達(dá)到最大承載能力。設(shè)計(jì)時(shí)以第二階段作為極限狀態(tài)。3、規(guī)范對(duì)施工縫留置及處理要求為使混凝土結(jié)構(gòu)具有較好的整體性, 混凝土的