a long-term project." Engineering quality is the lifeline of engineering construction, and water retention rate, as a key parameter affecting the performance of engineering materials and structural durability, is like an "invisible line of defense", which is directly related to the overall quality and long-term safety of the project. The water retention rate of cement mortar is an important parameter to evaluate the water retention capacity of cement mortar in the construction process, which directly determines whether the cement can be fully hydrated, whether the mortar has good workability and bonding force, and whether there will be insufficient strength, cracking, hollowing and other problems in the later period. Appropriate water retention rate can reduce water loss, avoid cracking or insufficient strength of mortar due to lack of water, and improve plasticity and fluidity. Water retention rate detection of cement mortar is an important means to standardize production and ensure product quality, to avoid unqualified mortar entering the construction site, and ultimately to protect the safety and durability of the project. Therefore, in today's increasingly pursuit of refinement and standardization in engineering construction, precise control of water retention rate, laboratory as the "eye" of cement quality control. The water retention rate of masonry cement mortar must be strictly tested and controlled according to GB/T 3183-2025 "Masonry Cement" and GB/T 45002-2024 "Determination of Water Retention Rate of Cement Mortar" to ensure the quality and safety of construction projects. In 2022, a cement company affiliated to a cement enterprise group in Hubei Province, due to the quality control effect of the cement process, the 45um sieve fineness of M32.5 cement fluctuated greatly and continuously exceeded the internal control index, resulting in a large area of hollowing of the batch of M32.5 cement for the decoration and tiling of buildings in Jingshan City, Hubei Province, and demanding a claim of more than 1 million yuan for rework, which not only caused economic losses to the company. It also has a negative social impact on the company's cement brand reputation.
Moisture is the "double-edged sword" of materials: in concrete engineering, water is a necessary condition for cement hydration reaction and strength acquisition, but excessive free water residue or improper evaporation will lead to increased porosity, reduced strength, dry shrinkage, hollowing and cracking, which will bury hidden dangers for durability. Water plays a complex and key role in engineering construction, and cement, as one of the building materials, must not only control the quality and performance of materials, but also control the fineness and mineral composition of cement, which directly affect the hydration rate and slurry viscosity, and at the same time, put an end to "adding water" in concrete grouting construction, otherwise "bleeding" of concrete. The low strength of concrete seriously affects the quality of the project. Therefore, the control of water retention rate is essentially a precise regulation of the internal "water environment" of engineering materials. Its pursuit is not simply "more" or "less", but to achieve the rational existence, effective utilization and orderly migration of water under the specific materials, cement ratio and grinding process. Precise control means that from the whole process of ingredient design, material selection, material ratio, concrete construction to maintenance, we should have a good idea of the "origin and development" of moisture.
Figure 2 Masonry M3 2.5 cement tile "empty drum" rework
to build a systematic network control of quality and accurately control the water retention rate: to lay a solid foundation for cement quality, it is necessary to upgrade the water retention rate control from point management to system engineering. As the testing and research department of cement working performance, the laboratory of cement plant first refines the source of cement ingredients, strictly controls the optimization and inspection of materials, and for the selection and use of cement admixtures, it is necessary to carry out the relevant cement proportioning grinding test and performance index testing test, lock in materials and proportioning, and strictly control the process quality, especially aiming at fineness. Dynamically adjust and control parameters in the grinding process, and strengthen daily detection and weekly monitoring. At the same time, integrating water retention rate control into quality management culture and accurately controlling water retention rate is not only a set of technical methods, but also a popular quality culture and management philosophy. Firstly, we should strengthen awareness education so that every quality manager, inspection technician and central control operator can deeply understand the extreme importance of water control to quality, and clarify their responsibilities in the "water conservation" chain. Secondly, we should improve the quality standards and assessment responsibility system, clarify the specific standards, control methods and responsible persons of water retention rate control in the design of performance appraisal indicators, post responsibilities and operation instructions, and establish a traceable and assessable responsibility system. Advocate giving priority to quality prevention, not "fire fighting" after the event, move the control focus forward to the stage of cement batching, manufacturing and inspection, strengthen the detection and monitoring of process performance indicators, timely detect and correct the signs that may lead to the loss of control of water retention rate, rather than repair afterwards.
"Everything important in the world must be done in detail." The quality of Shanghai Century Building, Three Gorges Dam and other national key projects and century projects starts from the compactness of each concrete and the solidity of each roadbed. Accurate control of water retention rate is the key to "fine" and the foundation of "solid". It tests the professional ingenuity, management wisdom and responsibility of the builders. Only with a scientific and rigorous working attitude, water control runs through every link of the life cycle of the project, carefully carved, and prevented the gradual decline, can we cast high-quality products, truly lay a solid foundation for the quality of the project, and deliver high-quality projects that can stand the test of time. To contribute a solid force from a "big cement country" to a "strong cement country". (Group Headquarters: yuan Changcheng)
浙公网安备33010802003254号