7 results about "Saturated-surface-dry" patented technology

The application discloses a kind of liquid-solid abrasion under concrete quality loss rate evaluation method and device, belong to civil engineering field.Concrete quality loss rate prediction model is defined, the saturated surface dry mass loss of concrete test piece before and after liquid-solid abrasion effect of different scouring rate, scouring angle, silt content is obtained by abrasion accelerated test, and the concrete quality loss rate is calculated;The calculated value of concrete quality loss rate is substituted into prediction model, and the to-be-solved parameter is fitted to obtain;The to-be-solved parameter fitted to obtain is substituted into prediction model, and the concrete quality loss rate under the liquid-solid abrasion effect of different scouring rate, scouring angle, scouring time, silt content is predicted using model.The abrasion accelerated test described above is realized using concrete quality loss rate test device.The abrasion of concrete member under the condition of different scouring rate, scouring angle, silt content in sea area can be realized by the present application to predict the quality loss rate.

The invention discloses a method for measuring saturated surface dry water absorption of regenerated fine aggregate, and belongs to the technical field of building material testing. The method adopts a two-step method to separate free water on the surface of the regenerated fine aggregate, and comprises the following steps: firstly, rapidly removing free water among particles of the soaked saturated regenerated fine aggregate and on the surface of part of the particles through a centrifugal method; secondly, the evaporation rate of free water on the surface of the regenerated fine aggregate is controlled through a temperature control evaporation method; and then judging the saturated surface dry state of the regenerated fine aggregate by adopting a second inflection point appearing at a rapid descending section of the time and moisture content curve, thereby determining the saturated surface dry water absorption rate of the regenerated fine aggregate. According to the method, the saturated surface dry standard state and the corresponding saturated surface dry water absorption rate of the regenerated fine aggregate can be effectively determined, the conversion from qualitative evaluation to quantitative evaluation is realized, and the method is also suitable for testing the saturated surface dry water absorption rate of fine particles such as natural fine aggregate and machine-made sand.

The application provides a kind of iron tailings sand-containing machine-made sand concrete and a preparation method thereof, relates to the technical field of building materials and solid waste resource utilization, and includes obtaining iron tailings sand and machine-made sand, respectively detecting the fineness modulus, 0.075mm below particle content, water absorption and moisture content of the iron tailings sand, and the fineness modulus, stone powder content, water absorption and moisture content of the machine-made sand.The iron tailings sand-containing machine-made sand concrete and the preparation method thereof detect the performance state of the iron tailings sand and the machine-made sand, and combine saturated surface dry conversion, mixing water correction, pre-wetting correction, compound control and segmented mixing, etc.Processing flow, effectively regulate the preparation process of composite fine aggregate, thereby improving the mix proportion adaptability and preparation stability of the iron tailings sand-containing machine-made sand concrete, and reducing the workability fluctuation and performance instability caused by the difference in particle composition and water absorption characteristics of the two types of fine aggregate.

The application discloses a pre-mixed high-density compensation shrinkage wet spraying concrete yield shear stress regulation method and relates to the technical field of wet spraying concrete of hydraulic underground caverns, which comprises the following steps: S1, determining a yield shear stress target value τ0,targ in advance; and S2, according to the design strength and the slump, initially selecting the high-density compensation shrinkage wet spraying concrete water-binder ratio W / B, the cement mass mc, the silica fume mass msi, the expansive agent mass mexp, the water consumption mw, the water reducing agent mass mwr, the saturated surface dry state aggregate total mass ma and the mass fraction mPa,i of each particle size aggregate mixing ratio parameters. The application solves the wet spraying concrete mixing ratio production regulation and control problem oriented by the yield shear stress in the wet spraying construction process, realizes the wet spraying concrete production mixing ratio optimization adjustment based on the target yield shear stress, significantly reduces the rebound rate and the pipe blocking probability, and has obvious economic and social benefits.

The invention relates to the technical field of constructional engineering construction, and discloses a metro depot track prefabricated column grouting construction method which comprises the following steps that firstly, a prefabricated column is positioned above a structural bottom plate, and a grouting gap at the bottom is sealed through a plugging assembly comprising a rigid hoop and a flexible liner; then, a grouting device is connected to the lower grouting hole, and grouting materials are pumped from bottom to top to fill an inner cavity; when thick slurry overflows from the upper slurry outlet hole, pumping is stopped, a gravity slurry supplementing device is connected to the highest interface of the top surface, and other orifices are closed; injecting slurry into the funnel container to enable the liquid level to be higher than the top surface of the prefabricated column, supplementing the slurry into the funnel container by utilizing hydrostatic pressure until the liquid level is stable and does not descend any more, and sealing the hole. According to the method, the saturated surface dry treatment of the base surface and the rheological property control of the slurry are combined, through the two-stage operation of mechanical grouting and high-position gravity slurry supplementing, internal air bags and shrinkage disengaging are effectively eliminated, and the compactness and integrity of the prefabricated column connecting joint are guaranteed.

The application discloses a kind of low additional water full recycled concrete based on recycled fine aggregate wet packing gradation optimization and preparation method thereof, belong to building material technical field.The application is classified into three intervals by natural gradation recycled fine aggregate, after pre-wetting to saturated surface dry state, the wet loose bulk density under each mass proportion combination is determined, and the highest density is selected as the optimal artificial gradation;60% of the saturated surface dry water absorption of all recycled aggregates is determined as additional water;cement, recycled fine aggregate, recycled coarse aggregate, initial water and water reducing agent are used to prepare by using the layered feeding process of "cement pre-mixing→ neat paste preparation→ coarse aggregate→ fine aggregate".The obtained concrete has a slump of 160-190mm, a 28-day compressive strength of 25-40MPa, good fluidity, can meet the construction requirements of conventional concrete structure, and does not need chemical modification, low cost, suitable for building solid waste large-scale utilization.

The utility model belongs to the field of engineering design, and particularly discloses a fine aggregate saturated surface dry state quantitative spraying and stirring device for assisting fine aggregate density and water absorption tests, which comprises a base, a stand column fixed on the base, a cross rod movably connected with the top end of the stand column, and one end of the cross rod capable of rotating around the top end of the stand column. Through the arrangement of the quantitative sprayer and the stirrer, not only can the amount of water added each time be accurately controlled, but also atomization spraying adding is implemented, and the materials are uniformly dispersed in the aggregate under the assistance of mechanical stirring, so that the aggregate can reach a saturated surface dry state more quickly, and subsequent tests are facilitated.