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Current hot topics in precast assembled concrete bridges
As a requirement for structural performance, normal usability and durability are also important.
Relatively speaking, the research on the normal performance and durability of precast concrete bridges is still somewhat insufficient, which may limit the application scope of precast concrete bridges.
Taking railway bridges as an example, due to the needs of train safety and passenger comfort, both conventional and high-speed railways have high requirements for the deformation and stiffness of bridge beams and piers.
Conducting research on the normal performance of precast concrete bridges for railway construction is an inevitable requirement for promoting the application of precast assembly technology in railway bridges.
As a critical infrastructure, the performance degradation mechanism and characteristics of precast assembly nodes, non-destructive testing methods, and corresponding reinforcement technologies are important issues that need to be addressed to ensure the durability of precast assembly concrete bridges in complex environments after a long service life.
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Analysis of factors affecting the flexural strength of cement concrete pavement
As the main cementitious material of concrete, the quality of cement largely determines the quality of concrete, especially in pavement concrete, which not only requires compressive and flexural strength that meets the specifications, but also has relatively high requirements for fatigue resistance, impact resistance, and abrasion resistance after cement hardening.
In cement clinker, it is beneficial to increase the C4AF and C2S content appropriately to improve the fatigue resistance, impact resistance, and wear resistance of concrete while ensuring sufficient C3S content to meet strength requirements and a flux mineral content of 19% to 20%.
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How to evaluate the insufficient 28 day rebound strength of C40 concrete
Q: The rebound strength of the C40 column is approximately 33.
35, and there is no problem with the test block.
Is it due to on-site reasons (such as vibration and curing?) If measures are taken later, can the strength still improve?.
Summary of Leakage Treatment Measures for Hydraulic Concrete Buildings
The leakage of hydraulic concrete structures is a common and major damage phenomenon in hydraulic structures.
According to the different locations where it occurs, it can be divided into several types: leakage of the building itself, leakage of the foundation, leakage of the contact surface between the bottom plate and the foundation, and leakage around the side.
Based on years of practical experience, the following measures can be taken to address the various types of leaks mentioned above.
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Life and death crisis in the concrete industry: 3% to 13%, 3 iron rules for survival
After January 1, 2026, all invoices issued at a 3% tax rate must be flushed and reissued to 13%.
Don’t have any luck mentality, the tax system has been fully monitored, and delaying will only face fines and late fees.
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Farewell to the ‘Simple Era’: Compliance Storm and Survival Rules of Unified 13% Value Added Tax Rate in the Concrete Industry
Over the past decade, in order to encourage the comprehensive utilization of resources and simplify tax management, according to the “Notice of the Ministry of Finance and the State Administration of Taxation on the Application of Low Value Added Tax Rates and Simplified Methods for Value Added Tax Collection on Some Goods” (Caishui [2009] No.
9), general taxpayers selling self-produced commercial concrete (limited to cement concrete produced from cement as raw material) can choose to pay value-added tax at a simplified rate of 3% according to the simplified method.
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Essential skills for delivery inspection of ready mixed concrete
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The construction unit shall inspect the “Pre mixed Concrete Delivery Note” and pre mixed concrete certificate, the factory time, and record the entry time of the mixing and transportation vehicle.
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The Nature journal of Purdue University in the United States published an article: Simultaneously solving the rheological, mechanical, and
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: Cellulose nanofibers and limestone fillers help achieve high-performance, sustainable, and cost-effective printable concrete.
Design of Permeable Cement Concrete Pavement
Permeable cement concrete pavement is divided into semi permeable pavement and fully permeable pavement, and its application range and pavement structure can be selected according to Table 1.
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