CN110434991B

CN110434991B - Steam curing process for precast concrete member

Info

Publication number: CN110434991B
Application number: CN201910736267.XA
Authority: CN
Inventors: 江龙
Original assignee: Guangdong Donghong Technology Co ltd
Current assignee: Guangdong Donghong Zhugong Technology Co., Ltd
Priority date: 2019-08-10
Filing date: 2019-08-10
Publication date: 2021-11-30
Anticipated expiration: 2039-08-10
Also published as: CN110434991A

Abstract

A precast concrete member steam curing process is characterized in that a precast concrete member is placed in a steam curing cover with an even heat transfer part for steam curing, so that the surface temperature of the concrete member is even, after curing in four stages of pre-curing, heating, constant temperature and cooling, the curing cover is opened to finish concrete curing, and therefore the performance of the steam cured concrete member can be improved.

Description

Steam curing process for precast concrete member

Technical Field

The invention relates to a production flow of a concrete member, in particular to a steam curing process of a precast concrete member.

Background

With the development of society and the continuous progress of production technology, the fabricated structure becomes a new direction for the development of the concrete structure at present and also becomes a structural form for the key popularization and application of the country in future. The most important concrete prefabricated part in the assembled structure can greatly improve the appearance quality of concrete through factory production, the structural performance of the concrete prefabricated part can be strictly controlled, and meanwhile, the concrete prefabricated part also has the advantages of being capable of greatly improving the environmental conditions of a construction site, saving raw materials, accelerating the construction speed, being capable of being repeatedly used and the like.

Concrete member production enterprises adopt automatic production lines such as complete concrete stirring, pouring, conveying, curing, kiln discharging and the like to meet the requirements of production of various concrete prefabricated members and quality control of finished products. Concrete is a hydraulic material, and concrete curing is an important process for ensuring the quality of concrete. In the concrete strength increasing period, in order to avoid the water loss caused by surface evaporation and other reasons, fully perform the hydration action of the concrete and ensure the technical indexes of the strength, the durability and the like of the concrete, the concrete must be maintained.

The steam curing technology is one of the most applied methods for curing concrete as a mature concrete curing technology, is one of important ways for improving the strength of concrete, and is one of methods for shortening the curing time. The steam curing of concrete is generally divided into four stages of pre-curing, temperature rising, constant temperature and temperature lowering, and the structural damage and crack generation of concrete mainly occur in the temperature rising period and the temperature lowering period.

The existing steam curing equipment is mainly provided with a steam curing kiln and a steam curing shed aiming at large prefabricated parts, all concrete parts are placed in the steam curing kiln and the steam curing shed, the temperature and the humidity of the whole area are controlled, the occupied space is large, the energy consumption is high, and the investment is large. When the small components are steamed, the special steaming cover with a hard structure or a soft structure is adopted, and the single prefabricated components are placed in the special steaming cover for steaming, so that the effects of light weight, energy conservation and controllability can be realized. In a small steam curing system for precast concrete members, the special steam curing cover has small space, and steam input from a single steam outlet directly reaches the surface of the concrete member, so that the surface temperature of the plate-shaped concrete member is uneven, and the performance of the concrete member is affected particularly in a temperature rise period and a temperature drop period; therefore, a plurality of steam outlets are usually required to be arranged for inputting steam simultaneously, and for concrete members with different sizes, corresponding steam outlets are required to be arranged respectively, so that the process is complicated.

Disclosure of Invention

The invention provides a steam curing process for a precast concrete member, which can solve the problems in the prior art.

As an aspect of the present invention, there is provided a precast concrete unit steam curing system including: the maintenance bracket is used for placing a concrete member to be maintained; the curing cover is used for accommodating the curing support and the concrete member, and a concrete curing environment is formed in the curing cover; a steam input system comprising a single air outlet for blowing a stream of steam at a specified temperature and humidity over the concrete element; the concrete member is centrally positioned below the air outlet, and the air outlet structure further comprises a uniform heat transfer part arranged on the concrete member and having a structure extending outwards from the center, so that the space between the uniform heat transfer part and the upper surface of the concrete member is gradually reduced outwards from the center.

Preferably, the material of the uniform heat transfer part is a material with good heat conductivity.

Preferably, the material of the uniform heat transfer portion is metal.

Preferably, the concrete member is a plate-like member that is placed across the curing bracket.

Preferably, the volume of the housing corresponds to the volume of the concrete element, the interior of which can accommodate only a single concrete element.

Preferably, the device further comprises a temperature sensing device and a humidity sensing device which are arranged in the protective cover.

Preferably, the steam input system adjusts the temperature and the humidity of the input steam according to the detection results of the temperature sensing device and the humidity sensing device.

Preferably, the maintenance cover further comprises a pressure maintaining device, and when the pressure in the maintenance cover is greater than a set value, the pressure maintaining device exhausts the maintenance cover.

As another aspect of the present invention, there is provided a steam curing method of a precast concrete member, including the steps of: (1) opening the maintenance cover, and placing the precast concrete component to be maintained on the maintenance support; (2) arranging a uniform heat transfer part on the precast concrete member; (3) closing the curing hood, and inputting steam with specified temperature and humidity through a steam input system; (4) after curing in four stages of precuring, heating up, keeping constant temperature and cooling down, the curing cover is opened to finish the concrete.

Drawings

FIG. 1 is a schematic view of a steam curing system for precast concrete unit according to an embodiment of the present invention.

FIG. 2 is a flowchart of a steam curing method of a precast concrete unit according to an embodiment of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention. Moreover, it is to be understood that the features of the various embodiments described herein are not mutually exclusive and can exist in a wide variety of combinations and permutations.

The steam curing system for precast concrete members according to an embodiment of the present invention, which is used for steam curing of a concrete member 100, with reference to fig. 1, includes a curing bracket 10, a curing cover 20, a steam input system, a uniform heat transfer part 30, a temperature sensing device, a humidity sensing device, and a pressure maintaining device (not shown). And a curing bracket 10 for placing a concrete member 100 to be cured, wherein the concrete member 100 is a plate-shaped member which is transversely placed on the curing bracket 10. And a curing cover 20 for accommodating the curing bracket 10 and the concrete member 100, in which a concrete curing environment is formed. The curing hood 20 is a special curing hood for small concrete members, has a volume corresponding to the volume of the concrete member 100, and can accommodate only a single concrete member 100 therein. The steam input system is used for inputting steam into the curing hood 20 and comprises a single air outlet 40 positioned in the curing hood 20 and used for blowing steam airflow with specified temperature and humidity above the concrete member 100, and the center of the concrete member 100 is arranged below the single air outlet 40. The steam input system may use an electric steam generator, a fuel steam generator, or a gas steam generator as the steam source, with the flow of steam controlled by a solenoid valve. The temperature sensing device and the humidity sensing device are arranged in the curing cover 20 and used for detecting the temperature and the humidity in the curing cover 20, and the steam input system adjusts the temperature and the humidity of input steam according to the detection results of the temperature sensing device and the humidity sensing device, so that the temperature and the humidity in the curing cover 20 meet the steam curing condition. The pressure maintaining device comprises a pressure sensor and an outlet pipeline controlled by a solenoid valve, and when the pressure in the maintenance cover is greater than a set value, the pressure maintaining device exhausts the maintenance cover through the outlet pipeline, so that the pressure in the maintenance cover 20 meets the steam maintenance condition. The uniform heat transfer part 30 is disposed above the concrete member 100, and has a structure extending outward from the center, and may be curved or tapered such that a space 50 between the uniform heat transfer part 30 and the upper surface of the concrete member 100 is gradually reduced outward from the center. The material of the uniform heat transfer part 30 is a good heat conductor, such as copper, iron, aluminum, etc., and the steam output from the air outlet 40 contacts the uniform heat transfer part 30 and then conducts heat through the uniform heat transfer part 30, and since the air heat conductivity between the uniform heat transfer part 30 and the upper surface of the concrete member 100 is lower than that of metal, the time for the heat to reach the two sides of the concrete member after being transmitted to the two sides of the uniform heat transfer part 30 is closer to the time for the heat to be directly transmitted to the middle of the concrete member through air, so that the heat is uniformly transmitted to the surface of the concrete member, and the performance of the steam-cured concrete member is improved.

The steam curing method of the precast concrete member of the embodiment of the invention, referring to fig. 2, includes the following steps: (1) opening the maintenance cover, and placing the precast concrete component to be maintained on the maintenance support; (2) arranging a uniform heat transfer part on the precast concrete member; (3) closing the curing hood, and inputting steam with specified temperature and humidity through a steam input system; (4) after curing in four stages of precuring, heating up, keeping constant temperature and cooling down, the curing cover is opened to finish the curing of the concrete.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. The particular features, structures, materials, or characteristics described in this disclosure may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.

Claims

1. A precast concrete unit steam curing system for steam curing of small concrete units, comprising: the maintenance bracket is used for placing a concrete member to be maintained; the curing cover is used for accommodating the curing support and the concrete member, and a concrete curing environment is formed in the curing cover; a steam input system comprising a single air outlet for blowing a stream of steam at a specified temperature and humidity over the concrete element; the method is characterized in that: the single air outlet is positioned above the center of the small concrete member, the curing cover is a special steam curing cover for the small concrete member, the volume of the curing cover corresponds to that of the concrete member, and only a single concrete member can be accommodated in the curing cover; the concrete member is centrally arranged below the air outlet, and the concrete member further comprises a uniform heat transfer part arranged on the concrete member, wherein the uniform heat transfer part has a structure extending outwards from the center, so that the space between the uniform heat transfer part and the upper surface of the concrete member is gradually reduced outwards from the center; the temperature sensing device and the humidity sensing device are arranged in the maintenance cover; the steam input system adjusts the temperature and the humidity of input steam according to the detection results of the temperature sensing device and the humidity sensing device; and the pressure maintaining device exhausts the maintenance cover when the pressure in the maintenance cover is greater than a set value.

2. The precast concrete unit steam curing system of claim 1, wherein: the material of the uniform heat transfer part is a material with good heat conductivity.

3. The precast concrete unit steam curing system of claim 1, wherein: the material of the uniform heat transfer part is metal.

4. A precast concrete unit steam curing method using the precast concrete unit steam curing system of claim 1, comprising the steps of: (1) opening the maintenance cover, and placing the precast concrete component to be maintained on the maintenance support; (2) arranging a uniform heat transfer part on the precast concrete member; (3) closing the curing hood, and inputting steam with specified temperature and humidity through a steam input system; (4) after curing in four stages of precuring, heating up, keeping constant temperature and cooling down, the curing cover is opened to finish the curing of the concrete.