CN-121999935-A - Permeable concrete and strength prediction and design method thereof

Abstract

The invention discloses permeable concrete and a strength prediction and design method thereof, and belongs to the technical field of building materials. The method for predicting and designing the strength of the pervious concrete comprises the steps of S1, designing the standard strength of the non-porous concrete through the water-cement ratio, the cementing material and the additive, S2, constructing a bilinear strength prediction model, dividing the relationship between the strength of the pervious concrete and the porosity into two sections of linear interval fitting, S3, combining the target porosity, and determining the strength of the pervious concrete by using the bilinear strength prediction model. The 28-day compressive strength of the pervious concrete and the non-porous concrete under the same water-cement ratio condition are compared and analyzed, a piecewise linear relation model between the strength coefficient f c /f c0 and the porosity p is provided, and the thickness of the wrapped slurry is controlled by combining the aggregate stacking density, the slurry rate and the slurry yield stress, so that the designable and controllable forming of the pervious concrete is realized. The problems that the strength is difficult to predict, the porosity is difficult to accurately control and the thickness of the wrapped slurry is unquantifiable in the existing permeable concrete design are solved.

Inventors

• LU FENTING
• LI JIERU
• JIANG YAQING
• HU YUEYANG
• LI XIAOYANG

Assignees

• 皖江工学院
• 盐城工学院
• 马鞍山海螺水泥有限责任公司

Dates

Publication Date

20260508

Application Date

20260128

Claims (6)

1. 1. The method for predicting and designing the strength of the pervious concrete is characterized by comprising the following steps: the standard strength of the non-porous concrete is designed through the water-cement ratio, the cementing material and the additive; Constructing a bilinear strength prediction model, and dividing the relation between the strength and the porosity of the pervious concrete into two sections of linear interval fitting; And combining the target porosity, and determining the strength of the pervious concrete by using a bilinear strength prediction model.
2. 2. The method for predicting and designing the strength of pervious concrete according to claim 1, wherein the method comprises the following steps: the standard strength f c0 of the non-porous concrete is the compressive strength of standard curing for 28 days; The bilinear intensity prediction model is: (p<0.23)(1) (p≥0.23)(2) Wherein f c is the strength of the pervious concrete, f c0 is the compressive strength of the non-porous concrete 28d, MPa, and p is the porosity of the pervious concrete.
3. 3. The method for predicting and designing the strength of pervious concrete according to claim 2, wherein the porosity p is calculated according to formula (3); (3) Wherein APD is aggregate bulk density and V p is slurry rate.
4. 4. The method for predicting and designing the strength of the pervious concrete according to claim 3, wherein the design requirement of the target porosity of the pervious concrete is met by regulating and controlling the thickness of the aggregate coating.
5. 5. The method for predicting and designing the strength of pervious concrete according to claim 4, wherein the aggregate wrapping thickness APT is controlled by adjusting the slurry yield stress τ, and satisfies the following formula (4): (4) Wherein, the unit of APT is mm, and the unit of tau is Pa.
6. 6. A pervious concrete, characterized by being produced by the method for predicting and designing the strength of a pervious concrete according to any one of claims 1 to 5.

Description

Permeable concrete and strength prediction and design method thereof Technical Field The invention relates to the technical field of building materials, in particular to permeable concrete and a strength prediction and design method thereof. Background The permeable concrete is a porous concrete material with communicated pores, has bearing capacity and permeability, is widely applied to sponge city construction, permeable pavement and ecological landscape engineering, and the unique structure of the permeable concrete provides an effective technical approach for relieving urban waterlogging, supplying groundwater, improving heat island effect and promoting green infrastructure construction. The strength and the porosity are the most basic performance indexes of the pervious concrete, and the current standard CJJ-2009 (technical Specification of pervious Cement concrete pavement) (2023 edition) only prescribes the range of the water-cement ratio in the section of the design of the proportion of the pervious concrete, and does not give a relation formula of the strength and the porosity. And (3) searching: Chinese patent CN116759034A, publication day 2023, 9 and 15, discloses a design method of the mix proportion of pervious concrete based on the thickness of the mortar, wherein the data of the specific surface area of aggregate is obtained through the wrapping of silica gel liquid and the image processing, so that the ratio of the aggregate to the cement slurry is calculated according to the thickness of the mortar of the pervious concrete. The method provides a way for accurately controlling the porosity of the pervious concrete, but the testing process is too complex and difficult to be practically applied. Chinese patent CN117037955A, publication day 2023, 11 and 10, discloses that the permeable concrete mix ratio meeting the requirements is selected by cross checking the compressive strength and the osmotic coefficient based on the relationship between the permeable concrete density and the compressive strength and the osmotic coefficient with the permeable concrete density as a parameter. The method has a certain practical value, but the performance of the permeable concrete with a given proportion cannot be predicted. Chinese patent CN119724438a, publication day 2025, 3 and 28, discloses that, based on the functional relationship between the compressive strength and the water permeability coefficient and the coarse aggregate particle size, the water gel ratio and the target porosity, the coarse aggregate particle size, the water gel ratio and the porosity parameters meeting the requirements of the compressive strength and the water permeability coefficient of the water permeable concrete are obtained, but the influence of the non-porous reference concrete strength on the overall performance of the water permeable concrete is neglected, so that the design result is different from the actual engineering requirement. Therefore, how to build a prediction model which can accurately describe the relation between the strength and the porosity of the pervious concrete and give consideration to the reference strength of the non-porous concrete becomes a key technical problem in the research and the application of the current pervious concrete. Disclosure of Invention Technical problem to be solved by the invention Aiming at the problems that the strength is difficult to predict, the porosity is difficult to accurately control and the slurry wrapping thickness is unquantifiable in the design of the pervious concrete in the prior art, the invention provides the pervious concrete and the strength prediction and design method thereof, and establishes a prediction model which can accurately describe the relationship between the strength and the porosity of the pervious concrete and give consideration to the reference strength of the non-porous concrete, thereby improving the reference strength, obviously enhancing the bearing capacity on the premise of meeting the water permeability requirement and realizing the purpose of effectively balancing the water permeability and the mechanical property. Technical proposal In order to achieve the above purpose, the technical scheme provided by the invention is as follows: a method for predicting and designing the strength of pervious concrete comprises the following steps: S1, designing the standard strength of the non-porous concrete through the water-cement ratio, the cementing material and the additive; s2, constructing a bilinear strength prediction model, and dividing the relation between the strength and the porosity of the pervious concrete into two sections of linear interval fitting; S3, combining the target porosity, and determining the strength of the pervious concrete by using a bilinear strength prediction model. The further prediction and design method comprises the following specific steps: step 1, intensity prediction: The compressive strength f c and the po