CN110644502A

CN110644502A - Aluminate reinforced concrete fender post that later stage easily broke away

Info

Publication number: CN110644502A
Application number: CN201910948031.2A
Authority: CN
Inventors: 徐长节; 管凌霄; 可文海; 王兴陈; 丁海滨; 阮呈尚
Original assignee: East China Jiaotong University
Current assignee: East China Jiaotong University
Priority date: 2019-10-08
Filing date: 2019-10-08
Publication date: 2020-01-03

Abstract

The invention provides an aluminate reinforced concrete fender post easy to break at the later stage, which is characterized in that concrete of the fender post is made of aluminate cement, stirrups of a reinforcement cage are bound in an independent ring shape, the aluminate cement takes bauxite and limestone as raw materials, clinker with calcium aluminate as a main component and alumina content of about 50% is prepared by calcining, and then a hydraulic cementing material is prepared by grinding.

Description

Aluminate reinforced concrete fender post that later stage easily broke away

Technical Field

The invention relates to an aluminate reinforced concrete fender post easy to break in the later period, and belongs to the technical field of civil engineering.

Background

With the rapid development of urban construction, the problem of shortage of ground space is increasingly highlighted, the development and utilization of underground space become important measures for solving the shortage of ground space, and meanwhile, various foundation pit supporting technologies are continuously emerging for solving the problems encountered in foundation pit engineering. The reinforced concrete fender pile has the characteristics of simple process, reliable construction quality and the like, and is widely applied to foundation pit support. The reinforced concrete fender post belongs to a temporary structure, loses the original function after the construction of a basement is finished, and is still kept underground to inevitably influence the development of urban underground space in the future, for example, the reinforced concrete fender post becomes a barrier for the tunneling of a subway shield tunnel. Because the durability and the integrity of the conventional reinforced concrete fender post are very high, when the conventional reinforced concrete fender post becomes an obstacle and needs to be broken, a large amount of manpower and material resources are consumed, and simultaneously, the conventional reinforced concrete fender post is very difficult, so that the problems of construction period delay, resource waste and the like are caused.

Therefore, for the reinforced concrete fender post, the idea of easy removal in the later period is conceived on the premise of not influencing the working performance of the reinforced concrete fender post, and the reinforced concrete fender post is a technical problem with practical engineering significance.

Disclosure of Invention

The invention aims to solve the problems in the background, and provides an aluminate reinforced concrete fender post which is easy to break in the later period.

The technical scheme of the invention is that the aluminate reinforced concrete fender post easy to break at the later stage is characterized in that the concrete of the fender post is made of aluminate cement, and stirrups of a reinforcement cage are independently bound in a ring shape.

The aluminate cement is a hydraulic cementing material prepared by calcining bauxite and limestone serving as raw materials to prepare clinker which takes calcium aluminate as a main component and has the content of alumina of about 50 percent, and grinding.

The diameter of the enclosure pile is less than or equal to 1m, and the thickness of the protective layer of the reinforcement cage is not less than 60 mm.

An aluminate reinforced concrete fender post easy to break in later period comprises the following construction methods:

(1) construction preparation, washing the stirring equipment to prevent residual portland cement and lime on the equipment;

(2) preparing aluminate cement, adding water, aggregate, powder and an additive according to the calculated mixture ratio, and uniformly stirring; when in use, the prepared cement paste can be operated for 20 minutes, and is strictly prohibited from being stirred for 2 times, so that the cement paste is prepared within 20 minutes before being poured;

(3) manufacturing a reinforcement cage, wherein when the reinforcement cage is manufactured, stirrups adopt an independent annular binding mode instead of spiral stirrups; the thickness of the protective layer of the steel reinforcement cage is not less than 60mm, and the diameter of the enclosure pile is not more than 1 m;

(4) drilling and forming holes, wherein during hole forming, the prepared slurry cannot contain components such as calcium hydroxide and the like, and the slurry cannot be alkaline so as to prevent the slurry from reacting with aluminate cement in concrete during concrete pouring;

(5) putting down a reinforcement cage;

(6) pouring aluminate cement concrete, and watering and curing immediately after hardening.

The aluminate cement is used for manufacturing the concrete of the foundation pit fender post, so that the strength of the foundation pit fender post can be rapidly increased after the concrete is poured, and can be kept at the highest strength during excavation of the foundation pit.

The invention has the beneficial effects that the strength of the aluminate reinforced concrete fender post easy to break at the later stage provided by the invention can be gradually reduced to 40 percent ~ 50 percent of the highest strength after the foundation pit is finished, so that the later stage underground engineering construction is easy to break manually or mechanically when encountering the fender post, and the difficulty of breaking the fender post is greatly reduced.

Drawings

FIG. 1 is a flow chart of the construction of a fender post;

FIG. 2 is a longitudinal cross-sectional view of the fender post;

in the figure, 1 is an aluminate reinforced concrete fender post; 2 is the fender post diameter; 3, the thickness of the protective layer of the reinforcement cage; 4 is the main reinforcement of the reinforcement cage; and 5, a stirrup of the reinforcement cage.

Detailed Description

A specific embodiment of the present invention is shown in fig. 1.

FIG. 1 is a construction flow chart of the fender post of the present invention, wherein the concrete of the fender post is made of aluminate cement, the aluminate cement is made of bauxite and limestone, the aluminate cement is calcined to form clinker with calcium aluminate as the main component and alumina content of about 50%, and the clinker is ground to form a hydraulic cementing material.

The quality guarantee period of the aluminate cement is 45 days (from the date of delivery), the aluminate cement is forbidden to use after the expiration, and sun protection and moisture protection are required during transportation and storage.

Before the aluminate cement is used for preparing concrete, the stirring equipment must be washed clean so as to prevent the silicate cement, lime and the like which are remained on the equipment from reacting with the equipment and influencing the quality of the aluminate cement.

The aluminate cement has simple use method, and can be prepared by only adding water, aggregate, powder, additive and the like according to the calculated mixing proportion and stirring uniformly. In use, the prepared cement slurry can be set up for 20 minutes, with 2 rigorous stirs being prohibited, and should therefore be prepared within 20 minutes prior to pouring.

When the fender post is formed into a hole, the prepared slurry cannot contain components such as calcium hydroxide and the like, the slurry cannot be alkaline, so that the slurry is prevented from reacting with aluminate cement in concrete when the concrete is poured, and watering and maintenance are carried out immediately after the fender post is poured with the concrete and is hardened.

Fig. 2 is a longitudinal sectional view of a fender post, wherein 1 is an aluminate reinforced concrete fender post; 2 is the diameter of the fender pile; 3, the thickness of the protective layer of the reinforcement cage; 4 is the main reinforcement of the reinforcement cage; and 5, a stirrup of the reinforcement cage.

The concrete of the enclosure pile is made of aluminate cement, the thickness of the protective layer of the steel reinforcement cage is not less than 60mm, and the diameter of the enclosure pile is less than or equal to 1m as much as possible.

The steel reinforcement cage of fender pile is considered when making, and the fender pile later stage is changeed in breaking away, and the stirrup adopts independent annular ligature mode, rather than spiral stirrup.

Claims

1. The aluminate reinforced concrete fender post easy to break at the later stage is characterized in that the concrete of the fender post is made of aluminate cement, and stirrups of a reinforcement cage are independently bound in an annular mode.

2. The aluminate reinforced concrete fender post easy to break at a later stage according to claim 1, wherein the aluminate cement is a hydraulic cementing material prepared by calcining bauxite and limestone to prepare clinker with calcium aluminate as a main component and alumina content of about 50%, and then grinding.

3. The aluminate reinforced concrete fender post easy to break at a later stage according to claim 1, wherein the diameter of the fender post is less than or equal to 1m, and the thickness of the reinforcement cage protective layer is not less than 60 mm.

4. The aluminate reinforced concrete fender post easy to break at a later stage according to claim 1, wherein the fender post is constructed by the following method:

(2) preparing aluminate cement, adding water, aggregate, powder and an additive according to the calculated mixture ratio, and uniformly stirring; when in use, the prepared cement paste is operated for 20 minutes, and the stirring is strictly prohibited for 2 times, so the cement paste is prepared within 20 minutes before the pouring;

(3) manufacturing a reinforcement cage, wherein when the reinforcement cage is manufactured, stirrups adopt an independent annular binding mode instead of spiral stirrups; the thickness of the protective layer of the steel reinforcement cage is not less than 60mm, and the diameter of the enclosure pile is less than or equal to 1m as much as possible;

(5) putting down a reinforcement cage;