CN1193002A

CN1193002A - Method for preparing high-performance concrete and construction technology thereof

Info

Publication number: CN1193002A
Application number: CN 97100662
Authority: CN
Inventors: 路来军; 吴存堂; 王兴辉; 卢明法; 刘明均
Original assignee: CONCRETE BRANCH Co BEIJING CITY CONSTRUCTION GROUP GENERAL CORP
Current assignee: CONCRETE BRANCH Co BEIJING CITY CONSTRUCTION GROUP GENERAL CORP
Priority date: 1997-03-10
Filing date: 1997-03-10
Publication date: 1998-09-16

Abstract

The present invention relates to a method for preparing high-performance concrete and its construction method. It is made up by using portland cememnt or general portland cement as main ingredient, adding additive (which is composite water-reducing agent or composite antifreezing agent containing plastic-retaining agent) and 8-30% Ca-Al-Si composite admixture, also adding 8-15% expanding agent. Its strength grade reaches to C80-C120, and its compactness is good, and can prevent the concrete surface from producing crack. Besides, said invented concrete possesses good fluidity, so that it is suitable for large-scale pumping construction.

Description

The compound method of high performance concrete and operating technique

The utility model relates to a kind of concrete compound method and operating technique, particularly a kind of compound method of high performance concrete of C80-C120 strength grade and operating technique.

In China, average strength grade of concrete is paced up and down for a long time in the backward level of C20-C30, and " fat beams and columns " stands in great numbers in the buildings, and " dark basic weight lid " is beset with.Strengthen dead load, increased materials consumption, caused unnecessary waste.Along with the development of urban construction and the progress of operating technique, in some large scale structures, Highrise buildings, railway engineering and public works, usually need C50-C60, even the pumpable concrete of C70-C120 intensity, therefore, impelling concrete is the task of top priority of construction industry to high-strength, lightweight, upper flow regime, high-durability development.The compound method of high-strength concrete is a lot, but how to realize with cement of high index (more than the 525#) and increasing cement consumption.Pei Zhi high-strength concrete because cement consumption is big, is concentrated the hydration heat height like this, causes shrinkage crack easily, so can't carry out the construction of big physique structure, the output of adding cement of high index is little, and the price height causes the concrete cost higher.Adopting the admixture technical elements, general compound method mainly is by reducing the mixing water amount, reduce the concrete voidage, reduce the formation in macropore and harmful hole, improving concrete pore structure.But the minimizing of mixing water will cause the slump less than normal, and will be mobile poor, pumping construction on a large scale, and perhaps under the situation of flowability difference, slump-loss is big, can't satisfy construction requirement.

The compound method and the operating technique that the purpose of this invention is to provide a kind of high performance concrete, make concrete can satisfy high strength, energy large-area construction, uninterrupted pumping, keep good workability for a long time, solve high-strength concrete because its surface compressed crack problem that gel material content brings greatly.

The technical solution of the utility model is:

A kind of compound method of high performance concrete is a main component with silicate cement or ordinary Portland cement, adds admixture and calcium aluminium silicon composite blend, it is characterized in that:

Also add the swelling agent of forming with Tai-Ace S 150, aluminum oxide, sulphur potassium aluminate and calcium sulfate, its volume is the 8-15% of cement;

Admixture is the composite water-reducing agent that contains retardant, air entrapment agent, high efficiency water reducing agent and plasticity-retention agent, and plasticity-retention agent contains polyphosphoric acid salt or tartrate, and volume is the 0.05-0.10% of cement weight;

In the winter time, above-mentioned admixture is the compound antifreezer that contains 0.8-0.12% calcium sulfite, hardening accelerator, water reducer, air entrapment agent.

The compound spike of calcium aluminium silicon is silicon-dioxide 45-75%, and the ground slag powder of aluminium sesquioxide 15-40%, its volume are the 8-30% of cement weight.

The operating technique of this high performance concrete, construction procedure is:

(1), formwork; (2), deposit concrete; (3), vibrate; (4), levelling, wipe one's face; (5) maintenance; (6), form removal; It is characterized in that: construction procedure is improved to

1), formwork;

2), with pumping method continuous concrete placing;

3), high frequency tamping;

4), levelling, wipe one's face;

5), cover immediately, water-preserving curing;

6), form removal when concrete strength reaches 10-15MPa, carry out water-preserving curing after the form removal immediately.

The present invention adds swelling agent, and concrete has been produced the compensate for shrinkage effect, makes the concrete can be owing to string stress produces the crack.Mix admixture and can reduce water cement ratio, increase flowability, reduce slump-loss, improve concrete strength, the close small bubbles of introducing have cut off concrete capillary channel, have improved concrete anti-permeability performance and weather resistance.Mix composite blend and can improve mixcibility soil workability and pumpability, improve late strength of concrete and weather resistance.Mix compound additive and composite blend simultaneously, can filling concrete in concrete between the particle, cement and gather materials between the slit play the micro-aggregate effect.These particulates of while and free lime, high alkalinity aquation Calucium Silicate powder produces secondary reaction, generates the low alkalinity hydrated calcium silicate, strengthened base material, improved the cohesive strength of aggregate and agglutinate, made concrete compactness good, be difficult for the crack, physical and mechanical property improves greatly.

The utility model has the advantages that: high performance concrete can reach the C80-C120 strength grade, avoided concrete surface the crack to occur, good fluidity is at horizontal throw 300m, the extensive continuous pouring construction of pumping can be taked in the vertical range 150m, excellent workability can be kept in 4 hours.With the C80 concrete replaced C 40 of this invention, deadweight can alleviate 40%, reduces cost 16%; If replaced C 35 is constant as weight, can save steel 40%, reduce cost 14%.Only Beijing can save concrete every year and invest 7,910 ten thousand yuan of people's coin, and can bear the erosion of severe environment, and extending structure reaches several centuries work-ing life, increases usage space 14%.Be specially adapted to the beam column etc. of railway, highway bridge and the Highrise buildings of large span.

Below in conjunction with embodiment the present invention is described in detail:

The compound method of this high performance concrete based on 525# silicate cement or ordinary Portland cement (folk prescription consumption 430-480 kilogram), adds admixture and calcium aluminium silicon composite blend;

Also add the swelling agent of forming with Tai-Ace S 150, aluminum oxide, sulphur potassium aluminate and calcium sulfate, its volume is the 8-15% of cement mixing content;

Admixture is with retardant (0.1-0.15%), air entrapment agent (0.005-0.01%), contains polyphosphoric acid salt or tartaric plasticity-retention agent (0.05-0.10%), how is or composite water-reducing agent that resene high efficiency water reducing agent (0.75-1.75%) is composited that volume is the 1-2% of cement weight; When winter construction, can add the compound antifreezer that contains 0.8-0.12% calcium sulfite, hardening accelerator, water reducer, air entrapment agent in the admixture, its volume is the 3-5% of cement weight.

The compound spike of calcium aluminium silicon is silicon-dioxide 45-75%, two kinds of ground slag powders of aluminium sesquioxide 15-40%, ratio in 1: 2～3 is composited, fineness is specific surface area 3000-7000 square centimeter/gram, its volume is the 8-30% of cement weight, making the concrete slump is 18-25cm, is convenient to the high performance concrete of big body construction.

1), formwork;

2), with pumping method continuous concrete placing;

3), high frequency tamping, the plum blossom shape is layouted, the pitch of holes of shaking is not more than 1.5m, every hole vibrating time should not be less than 30 seconds, the lift height that vibrates is not more than 60cm, when vibrating the last layer concrete, should inserting next layer concrete, to be no less than 10cm dark;

4), rapidly levelling, wipe one's face, before concrete is near initial set, answer the secondary rubbing and pressure, wipe one's face;

5), cover immediately, water-preserving curing;

6), form removal when concrete strength reaches 10-15MPa, carry out water-preserving curing after the form removal immediately, curing time is no less than 14 days.

Claims

1, a kind of compound method of high performance concrete is a main component with silicate cement or ordinary Portland cement, adds admixture and calcium aluminium silicon composite blend, it is characterized in that:

Also add the swelling agent that contains Tai-Ace S 150, aluminum oxide, sulphur potassium aluminate and calcium sulfate, its volume is the 8-15% of cement;

Admixture is the composite water-reducing agent that contains retardant, air entrapment agent, high efficiency water reducing agent and plasticity-retention agent, and plasticity-retention agent is polyphosphoric acid salt or tartrate, and volume is the 0.05-0.10% of cement weight;

2, the compound method of high performance concrete according to claim 1 is characterized in that: described admixture is the compound antifreezer that contains 0.8-0.12% calcium sulfite, hardening accelerator, water reducer, air entrapment agent.

3, a kind of operating technique of high performance concrete, its construction procedure is:

(1), formwork;

(2), deposit concrete;

(3), vibrate;

(4), levelling, wipe one's face;

(5), maintenance;

(6), form removal; It is characterized in that construction procedure is improved to:

(1), formwork;

(2), with pumping method continuous concrete placing;

(3), high frequency tamping;

(4), levelling, wipe one's face;

(5), cover immediately, water-preserving curing;

(6), form removal when concrete strength reaches 10-15MPa, carry out water-preserving curing after the form removal immediately.