Road cement concrete pavement strength index evaluation method

Abstract

The invention discloses a road cement concrete pavement strength index evaluation method. During rating of a field pavement slab, test results of the flexural strength of a joist test sample, the splitting tensile strength of a molded cylindrical test sample and the splitting tensile strength of a core sample decide whether the strength of the field pavement slab meet a requirement or not. For a low-grade road, just whether the molding splitting tensile strength meets the standard or not needs to be verified. For a high-grade road, the concepts of the molded cylindrical test sample and the molding splitting tensile strength are introduced, a comparison test for the molding splitting tensile strength, the splitting strength of the core sample and the flexural strength is performed through an indoor test, a mutual relation expression of the flexural strength, the molding splitting tensile strength and the splitting strength of the core sample is established in a regression way, the conventional conversion relation expression of the flexural strength and the splitting strength of the core sample is updated, the molding splitting strength converted from the splitting strength of the core sample is taken as a supplement index during acceptance, and a comprehensive strength index rating system is established to be taken as a rating basis for engineering quality acceptance.

Description

technical field [0001] The invention belongs to the technical field of cement concrete pavement, and relates to a strength index evaluation method of road cement concrete pavement. Background technique [0002] Cement concrete pavement has become the main type of pavement in my country. As of 2015, the ratio of cement pavement to all paved roads has increased to 73.5%. In the quality inspection of cement concrete pavement, the concrete bending and tensile strength is a key index, and the flexural strength of small beams is usually used as the strength inspection index in the construction process. When conducting quality sampling inspection after completion, core drilling is often used to measure the splitting strength. Refer to the formula Convert it to the flexural strength, and then evaluate the quality of the project. Therefore, the conversion relationship between flexural strength and splitting strength and the strength evaluation system are one of the focuses of high...

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Problems solved by technology

[0003] However, using the splitting tensile strength with a large difference in the force mode to test the flexural tensile strength has the problem that the design and acceptance indicators are not completely consistent.

Moreover, with the improvement of production technology, the accuracy of the conversion relationship between drill core splitting strength and flexural tensile strength proposed more than 20 years ago has dropped significantly, which may cause pavements whose mechanical properties do not meet the requirements to become "qualified" pavements during acceptance.

In recent years, early defects such as cracks, joints and floor voids often appear on cement concrete pavement, which has aroused our attention to the quality acceptance evaluation. Only a single flexural strength index is not perfect enough to evaluate the mechanical properties of the road. actual use requirements

[0004] At present, most countries adopt the flexural strength as the design index of road concrete. On-site acceptance is through testing the splitting strength of the core sample and converting it into flexural strength and comparing it with the design value. The conversion formula is generally determined by the researcher according to The derivation of local materials is naturally difficult to adapt to the source of raw materials in other regions. In practical applications, it is easy to cause the strength design target value of pavement concrete to be difficult to correspond and unify with the field acceptance measured value.

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