CN104960088A - Method for improving curve box girder appearance quality in high-temperature-difference region - Google Patents

Abstract

The invention discloses a method for improving curve box girder appearance quality in a high-temperature-difference region. The method comprises the steps of: solutions of high air temperature and large temperature difference factor influences: adjustment of concrete casting time and construction through avoiding from high-temperature time periods; reduction of concrete temperature; shortening of concrete time from discharge to mold entering; and solutions of high viscosity of concrete: adjustment of concrete mixing proportion under the precondition of fully guaranteeing concrete strength, reduction and reduction of utilization amount of unit concrete gel materials, and proper increment of sand percentage; and using transformer oil as a mold release agent to solve the problems of thickness and nonuniform texture of the mold release agent. After the method improves the construction method, the once pass percent of the box girder appearance is greatly improved to reach 91.8%, and the effect is prominent.

Description

A kind of method improving high temperature difference area curved box girder presentation quality

Technical field

The invention belongs to the realm of building construction, particularly relate to a kind of method improving high temperature difference area curved box girder presentation quality.

Background technology

In curved box girder prefabricated construction process, outward appearance occurs that the phenomenons such as bubble, water wave, crackle, faulting of slab ends are common quality problems.And curve paragraph case beam outward appearance is the focus place of pontic, in concrete structure, occur that appearance quality is also common quality defect the most common in concrete construction, improve this problem of presentation quality and not only there is realistic meaning, also there is facilitation to concrete construction from now on.

Be located in the area of high latitude, there is typical desert climate condition, day and night temperature macroclimate is dry, evaporation capacity large, construction environment is very severe, to ensureing that the unfavorable factor that the presentation quality of prefabricated case beam concrete component causes is more.

Merely for secondary decoration this, work work consuming is time-consuming and do not produce economic benefit, and ensuring the quality of products, under not increasing the prerequisite of construction cost, improving curved box girder presentation quality first-time qualification rate is problem in urgent need to solve.

Summary of the invention

The object of the present invention is to provide a kind of method improving high temperature difference area curved box girder presentation quality, be intended to ensure the quality of products, under not increasing the prerequisite of construction cost, improve curved box girder presentation quality first-time qualification rate.

The present invention is achieved in that a kind of method improving high temperature difference area curved box girder presentation quality comprises:

Step one, temperature are high, the solution of the large factor impact of the temperature difference: the adjustment concreting time, avoid the construction of high temperature period; Reduce concrete temperature; Shorten concrete from discharging to entering the mould time;

The solution of the large solution of step 2, concrete viscosity: adjust concrete mix under the prerequisite fully ensureing concrete strength, reduces and adjustment reduces unit concrete gel material consumption and increases sand coarse aggregate ratio in right amount;

Step 3, use transformer oil, as releasing agent, solve releasing agent thickness and the problem of quality inequality.

Further, described temperature is high, the solution of the large factor impact of the temperature difference also comprises:

Coagulate in concrete to the final set period and spread water in right amount to concrete roof surface coverage health preserving blanket and at health preserving blanket and template surface in advance, and reduce die plate temperature;

Concrete tank vehicle tank installs heat-preserving clothes additional;

Before charging with well water can,douche inside and outside to fall temperature in base concrete tank car tank body;

Taking to reduce tank car per car charging quantity, shortening concrete from discharging to entering the mould time.

Further, the solution of the large solution of described concrete viscosity is:

Reduce cement consumption, adjustment flyash and water reducer ratio, ensure the prerequisite decline low concrete viscosity of concrete quality index.

After improving construction method by method of the present invention, case beam outward appearance first-time qualification rate is largely increased, and reaches 91.8%, Be very effective.

Accompanying drawing explanation

Fig. 1 is the method flow diagram of the raising high temperature difference area curved box girder presentation quality that the embodiment of the present invention provides.

Detailed description of the invention

For summary of the invention of the present invention, Characteristic can be understood further, hereby exemplify following examples, and coordinate accompanying drawing to be described in detail as follows: the present invention does not exist the innovation of software or method.

Refer to Fig. 1:

The present invention is achieved in that a kind of method improving high temperature difference area curved box girder presentation quality comprises:

S101, temperature are high, the solution of the large factor impact of the temperature difference: the adjustment concreting time, avoid the construction of high temperature period; Reduce concrete temperature; Shorten concrete from discharging to entering the mould time;

The solution of the large solution of S102, concrete viscosity: adjust concrete mix under the prerequisite fully ensureing concrete strength, reduces and adjustment reduces unit concrete gel material consumption and increases sand coarse aggregate ratio in right amount;

S103, use transformer oil, as releasing agent, solve releasing agent thickness and the problem of quality inequality.

Further, the temperature described in S101 is high, the solution of the large factor impact of the temperature difference also comprises:

Coagulate in concrete to the final set period and spread water in right amount to concrete roof surface coverage health preserving blanket and at health preserving blanket and template surface in advance, and reduce die plate temperature;

Concrete tank vehicle tank installs heat-preserving clothes additional;

Before charging with well water can,douche inside and outside to fall temperature in base concrete tank car tank body;

Taking to reduce tank car per car charging quantity, shortening concrete from discharging to entering the mould time.

Further, the solution of the large solution of the concrete viscosity described in S102 is:

Reduce cement consumption, adjustment flyash and water reducer ratio, ensure the prerequisite decline low concrete viscosity of concrete quality index.

Embodiment one

The western access bridge total length 2840m of your Yellow River Bridge of Gande, Wuhai City, hole is across being distributed as 71 × 40m, and superstructure is 40m equal altitudes prestressed reinforced concrete case beam, and substructure is square column type framework pier shaft, and cast-in-situ bored pile connects cushion cap foundation; About bridge deck point, cloth is put, the wide 37m of bridge.The western access bridge of your Yellow River Bridge of Gande, Wuhai City, superstructure 71 hole 40m equal altitudes prestressed reinforced concrete prefabricated box-beam quantity is 852.This engineering place is located in high latitude area, has typical desert climate condition.Day and night temperature macroclimate is dry, evaporation capacity is large, construction environment is very severe, to ensureing that the unfavorable factor that the presentation quality of prefabricated case beam concrete component causes is more.

(1) solution that temperature is high, the temperature difference is large

First environmental quality residing for this area, night, comparatively daytime, wind-force reduced, temperature is relatively low and have a narrow range of temperature, evaporation capacity reduces relatively, first select adjustment concrete to start the time of building and just can reduce like this service behaviour decline that the bubble volume caused because temperature is too high becomes large and concrete causes soon due to high temperature dehydration, and coagulate in concrete to the final set period and spread to concrete roof surface coverage health preserving blanket and at health preserving blanket and template surface the moisture content that water takes away because of wind-force and temperature with supplementary concrete surface in right amount in advance, and reduce die plate temperature and make the bubble below template cause because die plate temperature is too high bubble volume to increase.Although avoid the construction of high temperature period every day, but the impact of the unfavorable factors such as the strong evaporation capacity of desert climate environment and high temperature still exists, make full use of field condition, mixing station industrial water is taken from the motor-pumped well of 100 meters, water temperature is at about 12 DEG C, with with taking out, the natural temperature of well water is utilized to reduce concrete drop temperature to reach the time (more than 10 DEG C can be reached through the maximum range of decrease of the concrete drop temperature of on-the-spot comparative determination) extending and keep concrete work performance; In addition, be reduce concrete temperature, extend the time keeping concrete work performance, also take following measures: 1. concrete tank vehicle tank installs heat-preserving clothes additional, 2. before charging with well water can,douche inside and outside to fall temperature in base concrete tank car tank body; 3. take to reduce tank car per car charging quantity, be down to 8 sides from 12 sides, shorten concrete from discharging to entering the mould time, effectively reducing the influence degree of hot environment to concrete work proterties.

Implementation result

By improving construction method, significantly reducing temperature is high, the temperature difference is large unfavorable factor to the influence degree of concrete work proterties, effectively reducing bubble phenomenon.

(2) solution that concrete viscosity is large

The principal element causing concrete viscosity large is the large quality with using water reducer of gel material content.By transferring laboratory's intensity detection report, concrete match ratio when quality inspection portion's Site Detection data analysis, determine to adopt the method for cement consumption and outer-penetrating agent ratio in adjustment concrete proportioning to reduce concrete viscosity, be determined by experiment reduction cement consumption, adjustment flyash and water reducer ratio, ensureing the prerequisite decline low concrete viscosity of concrete quality index, be beneficial to the discharge of bubble in concrete vibrating process.

Implementation result

By adjustment proportioning, reduce gel material content, case beam sides interior formwork obviously reduces, and reduces construction cost.

(3) releasing agent thickness and quality is uneven

In construction in early stage, releasing agent adopts and in machine oil, adds 30% diesel oil mixed liquor as releasing agent, easily form template local after brushing and occur that machine oil is concentrated, the comparatively sticky phenomenon of releasing agent, main cause be diesel oil add in machine oil stir insufficient, quality is uneven to be caused, after overtesting, use transformer oil instead as releasing agent, greatly reduce the viscosity of releasing agent and the thickness of attachment template.

Implementation result

By changing releasing agent, being beneficial to bubble and discharging, also improving concrete finish simultaneously.

By improving the first-time qualification rate investigation statistics table after construction method as shown in table 1-1:

Table 1-1

After improving construction method, case beam outward appearance first-time qualification rate obtains replying and improves, and reaches 91.8%, Be very effective.

The above is only to preferred embodiment of the present invention, not any pro forma restriction is done to the present invention, every according to technical spirit of the present invention to any simple modification made for any of the above embodiments, equivalent variations and modification, all belong in the scope of technical solution of the present invention.

Claims (3)

1. improve a method for high temperature difference area curved box girder presentation quality, it is characterized in that, the method for described raising high temperature difference area curved box girder presentation quality comprises:

Step one, temperature are high, the solution of the large factor impact of the temperature difference: the adjustment concreting time, avoid the construction of high temperature period; Reduce concrete temperature; Shorten concrete from discharging to entering the mould time;

The solution of the large solution of step 2, concrete viscosity: adjust concrete mix under the prerequisite fully ensureing concrete strength, reduces and adjustment reduces unit concrete gel material consumption and increases sand coarse aggregate ratio in right amount;

Step 3, use transformer oil, as releasing agent, solve releasing agent thickness and the problem of quality inequality.

2. the as claimed in claim 1 method improving high temperature difference area curved box girder presentation quality, is characterized in that, described temperature is high, the solution of the large factor impact of the temperature difference also comprises:

Coagulate in concrete to the final set period and spread water in right amount to concrete roof surface coverage health preserving blanket and at health preserving blanket and template surface in advance, and reduce die plate temperature;

Concrete tank vehicle tank installs heat-preserving clothes additional;

Before charging with well water can,douche inside and outside to fall temperature in base concrete tank car tank body;

Taking to reduce tank car per car charging quantity, shortening concrete from discharging to entering the mould time.

3. the method improving high temperature difference area curved box girder presentation quality as claimed in claim 1, it is characterized in that, the solution of the large solution of described concrete viscosity is:

Reduce cement consumption, adjustment flyash and water reducer ratio, ensure the prerequisite decline low concrete viscosity of concrete quality index.