Nanometer material modified geopolymer-based self-compacting concrete and construction process

Abstract

The invention relates to the field of nanometer materials, in particular to nanometer material modified geopolymer-based self-compacting concrete and a construction technology. According to the preparation method, the geopolymer is modified by the nano aluminum oxide, so that the compressive strength of the geopolymer-based self-compacting concrete can be remarkably improved. Researches show that the compressive strength of the geopolymer-based self-compacting concrete is in a trend of firstly increasing and then decreasing along with the increase of the particle size of the nanometer aluminum oxide, and in practice, in order to enable the 28d compressive strength of the concrete to be greater than 50MPa, the average particle size of the nanometer aluminum oxide is controlled to be 47nm-192nm.

Description

Technical Field

[0001] This invention relates to the field of nanomaterials, specifically to a nanomaterial-modified geopolymer-based self-compacting concrete and its construction process. Background Technology

[0002] Existing silicate cement production processes generate excessive carbon dioxide emissions, while geopolymers are considered a promising green and low-carbon alternative. Compared to ordinary concrete, geopolymer production can significantly reduce carbon dioxide emissions by approximately 80%. Among various geopolymer systems, those using fly ash and granulated blast furnace slag as primary precursors have broad application prospects due to their wide availability of raw materials, superior performance in some areas, and suitability for utilizing large quantities of industrial solid waste. Therefore, this invention aims to apply geopolymers to concrete to obtain high-performance concrete materials. Summary of the Invention

[0003] The purpose of this invention is to provide a nanomaterial-modified geopolymer-based self-compacting concrete with excellent 28-day compressive strength.

[0004] The technical solution of the present invention is as follows: A nanomaterial-modified geopolymer-based self-compacting concrete, the preparation process of which includes: Preparation of nano-alumina modified geopolymer slurry A: Mix 100-120g of fly ash and 50-60g of granulated blast furnace slag evenly, add to 200-220g of water, mix and stir, then add 32-35g of sodium silicate and 3.5-3.8g of sodium hydroxide, then add 12.5-14.0g of nano-alumina and stir evenly. The average particle size of the nano-alumina is 47-192nm. Preparation of nanomaterial-modified geopolymer-based self-compacting concrete: Add 60-80g of silicate cement, 1.8-2.0g of sodium sulfate, 0.8-0.9g of sodium stearate and 1.5-1.8g of polyacrylamide to 120-150g of water, mix and stir, and then pour into nano-alumina-modified geopolymer slurry A to obtain nanomaterial-modified geopolymer-based self-compacting concrete.

[0005] Preferably, the amount of fly ash used is 100g.

[0006] Preferably, the amount of granulated blast furnace slag used is 60g.

[0007] Preferably, the average particle size of the nano-alumina is 150 nm.

[0008] Preferably, the 28-day compressive strength of the concrete is greater than 50 MPa.

[0009] Preferably, the fly ash comprises: SiO2 42-43wt%, Al2O3 31-33wt%, CaO 8-9wt%, Fe2O3 5-6wt%, K2O 1.5-2.5wt%; and the granulated blast furnace slag comprises: SiO2 31-33wt%, Al2O3 15-16wt%, CaO 40-41wt%, MgO 4.5-5.5wt%, TiO2 1-2wt%.

[0010] Furthermore, the present invention also provides a construction process for a nanomaterial-modified geopolymer-based self-compacting concrete, wherein the construction process uses the aforementioned nanomaterial-modified geopolymer-based self-compacting concrete.

[0011] This invention utilizes nano-alumina to modify geopolymers, significantly improving the compressive strength of geopolymer-based self-compacting concrete. Studies show that as the particle size of nano-alumina increases, the compressive strength of geopolymer-based self-compacting concrete initially increases and then decreases. In practice, to achieve a 28-day compressive strength greater than 50 MPa, the average particle size of the nano-alumina should be controlled between 47 nm and 192 nm. This nanomaterial-modified geopolymer-based self-compacting concrete is suitable for use in post-cast strip connection areas. Detailed Implementation

[0012] The technical effects of the present invention will be verified through specific embodiments below, but the implementation of the present invention is not limited thereto.

[0013] The chemical compositions of fly ash and granulated blast furnace slag in this invention are shown in Table 1 and Table 2, respectively.

[0014] Table 1. Chemical composition of fly ash (wt%) Table 2 Chemical composition (wt%) of granulated blast furnace slag Example 1 Preparation of nano-alumina modified geopolymer slurry A: Mix 100g fly ash and 50g granulated blast furnace slag evenly, add to 200g water, mix and stir, then add 32g sodium silicate and 3.5g sodium hydroxide, then add 12.5g nano-alumina and stir evenly, wherein the average particle size of nano-alumina is 47nm; Preparation of nanomaterial-modified geopolymer-based self-compacting concrete: Add 80g silicate cement, 1.8g sodium sulfate, 0.8g sodium stearate and 1.5g polyacrylamide to 120g water, mix and stir, and then pour into nano-alumina-modified geopolymer slurry A to obtain nanomaterial-modified geopolymer-based self-compacting concrete.

[0015] Example 2 Preparation of nano-alumina modified geopolymer slurry A: Mix 100g fly ash and 50g granulated blast furnace slag evenly, add to 200g water, mix and stir, then add 32g sodium silicate and 3.5g sodium hydroxide, then add 12.5g nano-alumina and stir evenly, wherein the average particle size of nano-alumina is 60nm; Preparation of nanomaterial-modified geopolymer-based self-compacting concrete: Add 80g silicate cement, 1.8g sodium sulfate, 0.8g sodium stearate and 1.5g polyacrylamide to 120g water, mix and stir, and then pour into nano-alumina-modified geopolymer slurry A to obtain nanomaterial-modified geopolymer-based self-compacting concrete.

[0016] Example 3 Preparation of nano-alumina modified geopolymer slurry A: Mix 100g fly ash and 50g granulated blast furnace slag evenly, add to 200g water, mix and stir, then add 32g sodium silicate and 3.5g sodium hydroxide, then add 12.5g nano-alumina and stir evenly, wherein the average particle size of nano-alumina is 90nm; Preparation of nanomaterial-modified geopolymer-based self-compacting concrete: Add 80g silicate cement, 1.8g sodium sulfate, 0.8g sodium stearate and 1.5g polyacrylamide to 120g water, mix and stir, and then pour into nano-alumina-modified geopolymer slurry A to obtain nanomaterial-modified geopolymer-based self-compacting concrete.

[0017] Example 4 Preparation of nano-alumina modified geopolymer slurry A: Mix 100g fly ash and 50g granulated blast furnace slag evenly, add to 200g water, mix and stir, then add 32g sodium silicate and 3.5g sodium hydroxide, then add 12.5g nano-alumina and stir evenly, wherein the average particle size of nano-alumina is 150nm; Preparation of nanomaterial-modified geopolymer-based self-compacting concrete: Add 80g silicate cement, 1.8g sodium sulfate, 0.8g sodium stearate and 1.5g polyacrylamide to 120g water, mix and stir, and then pour into nano-alumina-modified geopolymer slurry A to obtain nanomaterial-modified geopolymer-based self-compacting concrete.

[0018] Example 5 Preparation of nano-alumina modified geopolymer slurry A: Mix 100g fly ash and 50g granulated blast furnace slag evenly, add to 200g water, mix and stir, then add 32g sodium silicate and 3.5g sodium hydroxide, then add 12.5g nano-alumina and stir evenly, wherein the average particle size of nano-alumina is 192nm; Preparation of nanomaterial-modified geopolymer-based self-compacting concrete: Add 80g silicate cement, 1.8g sodium sulfate, 0.8g sodium stearate and 1.5g polyacrylamide to 120g water, mix and stir, and then pour into nano-alumina-modified geopolymer slurry A to obtain nanomaterial-modified geopolymer-based self-compacting concrete.

[0019] Comparative Example 1 Preparation of nano-alumina modified geopolymer slurry A: Mix 100g fly ash and 50g granulated blast furnace slag evenly, add to 200g water, mix and stir, then add 32g sodium silicate and 3.5g sodium hydroxide, then add 12.5g nano-alumina and stir evenly, wherein the average particle size of nano-alumina is 20nm; Preparation of nanomaterial-modified geopolymer-based self-compacting concrete: Add 80g silicate cement, 1.8g sodium sulfate, 0.8g sodium stearate and 1.5g polyacrylamide to 120g water, mix and stir, and then pour into nano-alumina-modified geopolymer slurry A to obtain nanomaterial-modified geopolymer-based self-compacting concrete.

[0020] Comparative Example 2 Preparation of nano-alumina modified geopolymer slurry A: Mix 100g fly ash and 50g granulated blast furnace slag evenly, add to 200g water, mix and stir, then add 32g sodium silicate and 3.5g sodium hydroxide, then add 12.5g nano-alumina and stir evenly, wherein the average particle size of nano-alumina is 280nm; Preparation of nanomaterial-modified geopolymer-based self-compacting concrete: Add 80g silicate cement, 1.8g sodium sulfate, 0.8g sodium stearate and 1.5g polyacrylamide to 120g water, mix and stir, and then pour into nano-alumina-modified geopolymer slurry A to obtain nanomaterial-modified geopolymer-based self-compacting concrete.

[0021] Next, we evaluated the 28-day compressive strength (referring to GB / T50081-2002) of the experimental samples from Examples 1-5 and Comparative Examples 1-2, using geopolymer-based self-compacting concrete without nano-alumina as a control group. To ensure the comparability of the tests, all process conditions were identical except for the difference in the average particle size of the nano-alumina. The test results are shown in Table 1.

[0022] Table 1 Test data for each sample As shown in Table 1, modifying geopolymers with nano-alumina can significantly improve the compressive strength of geopolymer-based self-compacting concrete. With increasing nano-alumina particle size, the compressive strength of geopolymer-based self-compacting concrete exhibits a trend of first increasing and then decreasing. In practice, to achieve a 28-day compressive strength greater than 50 MPa, the average particle size of nano-alumina should be controlled between 47 nm and 192 nm.

[0023] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A nanomaterial-modified geopolymer-based self-compacting concrete, characterized in that, The preparation process of the nanomaterial-modified geopolymer-based self-compacting concrete includes: Preparation of nano-alumina modified geopolymer slurry A: Mix 100-120g of fly ash and 50-60g of granulated blast furnace slag evenly, add to 200-220g of water, mix and stir, then add 32-35g of sodium silicate and 3.5-3.8g of sodium hydroxide, then add 12.5-14.0g of nano-alumina and stir evenly. The average particle size of the nano-alumina is 47-192nm. Preparation of nanomaterial-modified geopolymer-based self-compacting concrete: Add 60-80g of silicate cement, 1.8-2.0g of sodium sulfate, 0.8-0.9g of sodium stearate and 1.5-1.8g of polyacrylamide to 120-150g of water, mix and stir, and then pour into nano-alumina-modified geopolymer slurry A to obtain nanomaterial-modified geopolymer-based self-compacting concrete.

2. A nanomaterial-modified geopolymer-based self-compacting concrete as described in claim 1, characterized in that, The amount of fly ash used is 100g.

3. A nanomaterial-modified geopolymer-based self-compacting concrete as described in claim 1, characterized in that, The amount of granulated blast furnace slag used is 60g.

4. A nanomaterial-modified geopolymer-based self-compacting concrete as described in claim 1, characterized in that, The average particle size of the nano-alumina is 150 nm.

5. A nanomaterial-modified geopolymer-based self-compacting concrete as described in claim 1, characterized in that, The 28-day compressive strength of the concrete is greater than 50 MPa.

6. A construction process for nanomaterial-modified geopolymer-based self-compacting concrete, characterized in that, The construction process uses the nanomaterial-modified geopolymer-based self-compacting concrete described in claim 1.

Images