CN103420647A - Conductive material co-doping conductive concrete and preparation method thereof - Google Patents

Abstract

The invention provides a conductive concrete compounded with conductive materials and a preparation method thereof. The concrete is composed of cement, silica fume, carbon fiber, carbon nanomaterials (carbon nanotubes + carbon black + graphite), nano-zinc oxide, water reducing agent, filling Material, dispersant, defoamer, and water. The preparation method of the multifunctional conductive concrete mixed with conductive materials is simple and the performance is excellent. Replacing some carbon fibers with carbon nanomaterials has lower cost and stable electrical conductivity than traditional conductive concrete. Adding nano-zinc oxide can significantly improve the electrical conductivity of concrete. In the case of electrification, the concrete has good electrothermal performance, and it is applied to airport pavement, bridge deck and cement concrete pavement. It can melt ice and snow, detect road loads, cracks and expansion of concrete structures; It has good electromagnetic properties, can effectively shield electromagnetic waves, reduce electromagnetic radiation, and reduce electromagnetic interference.

Description

Conductive concrete mixed with conductive material and preparation method thereof

technical field

The invention relates to the field of building materials, in particular to conductive concrete compounded with conductive materials and a preparation method thereof.

Background technique

  The problem of freezing and snow accumulation on the road surface in winter has always been the biggest problem in winter road maintenance in cold regions of our country. In the Northeast and Northwest of my country, snow falls early in winter and lasts for several months. The severe ice and snow weather is extremely unfavorable to the smooth flow of roads, railways, highways and airports and driving safety, and brings many inconveniences to people's life and production. In 2008, ice and snow covered 19 provinces across the country, causing large-scale traffic congestion and paralysis, and huge losses.

At present, the main methods of deicing and snow removal are manual and mechanical snow removal and chemical snow removal, but manual snow removal is time-consuming, laborious, inefficient, high in cost, unable to restore traffic in time, and has obvious lag; using snow melting agent or deicing salt to The infrastructure and the surrounding environment have adverse effects, and the use of physical methods to melt snow (thermal snow melting method) has gradually attracted the attention of scientific and technological workers.

Thermal snow melting methods include geothermal pipe method, infrared heating lamp method, electric heating wire method, fluid heating method, etc. The installation and construction of the geothermal pipe method is obviously complicated; the infrared heating lamp method is easily affected by the surrounding wind direction, and the temperature rises slowly, which is not conducive to rapid snow melting. Due to the movement of traffic, the heating wire will be pulled out of the asphalt concrete pavement layer; the fluid heating method needs to establish a system for melting ice and snow, but the construction of the system itself is troublesome, and the device requires a lot of capital investment. The hot water system is not easy to arrange, and it is more difficult Control, the heating effect is not ideal, when the automatic control system fails and the PVC pipe leaks, the hot water control system must stop working; the steel fiber in the steel fiber conductive concrete will rust in the concrete, and the resistance will increase with age increase.

Scientists have been experimenting with the manufacture of conductive concrete since the 1990s. Adding a small amount of conductive steel fiber or carbon fiber to the concrete, although the proportion is less than 1%, can make the concrete conductive; if the conductive concrete is compacted, the concrete will conduct electricity. The fibers will be dense and improve the conductive effect of concrete. The price of carbon fiber is high, and the resistivity of the prepared conductive concrete is relatively high, so it is not suitable for large-scale use.

Contents of the invention

The present invention provides a conductive concrete compounded with conductive materials and its preparation method. Carbon nanomaterials are used instead of carbon fibers, and nano-zinc oxide is added to improve conductivity and reduce costs.

The conductive concrete mixed with conductive material according to the present invention comprises the following components in parts by weight:

Cement, 20-40 parts;

Silica fume, 0-7 parts;

Carbon fiber, 0.25-2 parts;

Carbon nanomaterials, 0-2 parts;

Nano zinc oxide, 0.1-0.5 parts;

Water reducing agent, 0.02-0.3 parts;

Filling material, 50-150 parts;

Dispersant, 1.5-3.7 parts;

Defoamer, 0.1-0.3 parts;

Water, 8-21 parts.

As a further improvement, the particle size of the nanometer zinc oxide is 5-90nm.

Further improvement, described carbon nanomaterial is carbon nanotube, carbon black and graphite, and its mass ratio is carbon nanotube: carbon black: graphite=1: 6: 3.

The present invention also provides a kind of its preparation method of the conductive concrete mixed with conductive material, comprising the following steps:

1) Use physical and chemical composite dispersion technology to disperse carbon fiber, carbon nanomaterials and nano-zinc oxide for standby;

2) Stir cement, silica fume, and filler evenly, add dispersed carbon fiber, carbon nanomaterials, nano zinc oxide, water reducer, dispersant, and defoamer, and stir again to ensure that carbon fibers, carbon nanomaterials and nano Zinc oxide is evenly dispersed in concrete;

3) Pouring concrete, preliminary vibrating and smoothing;

4) According to the size of the aggregate particle size in the concrete, the electrodes used to connect the external circuit are embedded;

5) Vibrate again and assist in compaction to ensure a good connection between the copper mesh and the concrete.

As a further improvement, the electrode described in step 4) is a copper wire mesh.

The beneficial effects of the present invention are:

(1) The present invention adds nano-zinc oxide to the concrete, so that its resistivity is far lower than that of ordinary concrete, and its electrical conductivity is good;

(2) The preparation process is simple and easy, and carbon nanomaterials are used to replace carbon fibers, which reduces the cost.

(3) The concrete prepared by the present invention has good electrothermal performance when electrified, and can be applied to airport pavement, bridge deck and cement concrete pavement, and can melt ice and snow, detect road bearing load, cracks and expansion of concrete structures ; It has good electromagnetic performance without electricity, which can effectively shield electromagnetic waves, reduce electromagnetic radiation, and reduce electromagnetic interference.

(4) According to the requirements of use and construction conditions, suitable conductive materials can be selected to control the resistivity of conductive concrete, the conductive performance is stable, the electric heating performance is controllable, and its performance of melting ice and snow can be controlled. the

Detailed ways

The present invention will be further described below in conjunction with specific embodiment:

Embodiment 1 :

(1) The parts by weight of each component are:

Cement, 20 parts;

Silica fume, 0 parts;

Carbon fiber, 0.25 parts;

Carbon nanomaterials, 0 parts;

Nano zinc oxide, 0.1 part;

Water reducing agent, 0.02 part;

stuffing, 50 parts;

Dispersant, 1.5 parts;

Defoamer, 0.1 parts;

water, 8 parts.

(2) Preparation process:

1) Use physical and chemical composite dispersion technology to disperse carbon fiber, carbon nanomaterials and nano-zinc oxide for standby;

2) Stir cement, filler, carbon nanomaterials and nano-zinc oxide evenly, add dispersed carbon fiber, carbon nano-materials and nano-zinc oxide, then add water reducer, dispersant and defoamer;

3) Use copper mesh to make electrodes and insert them into concrete to connect to external circuits.

The resistivity of the 40×40×160mm conductive concrete test block prepared by the above components and methods after curing for 7 days, 28 days and 60 days at 20°C±2°C and relative humidity above 95% is 245.6Ω·cm and 248.3 Ω·cm and 249.5Ω·cm.

Embodiment 2 :

(1) The parts by weight of each component are:

Cement, 30 parts;

Silica fume, 3.5 parts;

carbon fiber, 0.5 parts;

Carbon nanomaterials, 1.0 parts;

Nano zinc oxide, 0.3 parts;

Water reducing agent, 0.02 part;

Filling material, 100 parts;

Dispersant, 2.6 parts;

Defoamer, 0.2 parts;

water, 15 parts.

(2) Preparation process:

1) Use physical and chemical composite dispersion technology to disperse carbon fiber, carbon nanomaterials and nano-zinc oxide for standby;

2) Mix cement, filler, silica fume and nano-zinc oxide evenly, add dispersed carbon fiber, carbon nano-materials and nano-zinc oxide, then add water reducer, dispersant and defoamer;

3) Use copper mesh to make electrodes and insert them into concrete to connect to external circuits.

The resistivity of the 40×40×160mm conductive concrete test block prepared by the above components and methods after curing for 7 days, 28 days and 60 days at 20℃±2℃ and relative humidity above 95% were 135.3Ω·cm and 137.2 Ω·cm and 138.8Ω·cm.

Embodiment 3 :

(1) The parts by weight of each component are:

Cement, 40 parts;

Silica fume, 7 parts;

carbon fiber, 1.5 parts;

Carbon nanomaterials, 2 parts;

Nano zinc oxide, 0.5 parts;

Water reducer, 0.3 parts;

stuffing, 150 parts;

Dispersant, 3.7 parts;

Defoamer, 0.3 parts;

water, 21 parts.

(2) Preparation process

1) Use physical and chemical composite dispersion technology to disperse carbon fiber, carbon nanomaterials and nano-zinc oxide for standby;

2) Mix cement, filler, silica fume and nano-zinc oxide evenly, add dispersed carbon fiber, carbon nano-materials and nano-zinc oxide, then add water reducer, dispersant and defoamer;

3) Use copper mesh to make electrodes and insert them into concrete to connect to external circuits.

The resistivity of the 40×40×160mm conductive concrete test block prepared by the above components and methods after curing for 7 days, 28 days and 60 days at 20℃±2℃ and relative humidity above 95% were 72.3Ω·cm and 74.5 Ω·cm and 75.9Ω·cm.

There are many ways of specific application of the present invention, and the above description is only a preferred embodiment of the present invention. It should be pointed out that for those of ordinary skill in the art, improvements can also be made without departing from the principles of the present invention. These improvements It should also be regarded as the protection scope of the present invention.

Claims (5)

1. a conductive concrete compounded with conductive material is characterized in that comprising the following components in parts by weight: Cement, 20-40 parts; Silica fume, 0-7 parts; Carbon fiber, 0.25-2 parts; Carbon nanomaterials, 0-2 parts; Nano zinc oxide, 0.1-0.5 parts; Water reducing agent, 0.02-0.3 parts; Filling material, 50-150 parts; Dispersant, 1.5-3.7 parts; Defoamer, 0.1-0.3 parts; Water, 8-21 parts. 2. The conductive concrete compounded with conductive materials according to claim 1, characterized in that: the particle size of the nano zinc oxide is 5-90nm. 3. a kind of conductive concrete mixed with conductive material according to claim 1, is characterized in that: described carbon nanomaterial is carbon nanotube, carbon black and graphite, and its mass ratio is carbon nanotube: carbon black: Graphite=1:6:3. 4. a preparation method of the conductive concrete compounded with conductive material according to claim 1, is characterized in that comprising the following steps: 1) Use physical and chemical composite dispersion technology to disperse carbon fiber, carbon nanomaterials and nano-zinc oxide for standby; 2) Stir cement, silica fume, and filler evenly, add dispersed carbon fiber, carbon nanomaterials, nano zinc oxide, water reducer, dispersant, and defoamer, and stir again to ensure that carbon fibers, carbon nanomaterials and nano Zinc oxide is evenly dispersed in concrete; 3) Pouring concrete, preliminary vibrating and smoothing; 4) According to the size of the aggregate particle size in the concrete, the electrodes used to connect the external circuit are embedded; 5) Vibrate again and assist in compaction to ensure a good connection between the copper mesh and the concrete. 5. The method for preparing conductive concrete compounded with conductive materials according to claim 3, characterized in that: the electrodes in step 4) are copper wire mesh.