Study On Presumption Of Clay Powder Content In Manufactured Sand And Its Influence On Dosage Of Water Reducing Admixture

The powder content of the mechanism sand determines the quality of the mechanism sand to a certain extent.And the MB value test of mechanism sand powder can only qualitatively reflect whether the powder smaller than 0.075 mm is mainly parent rock ore powder(limestone powder in this thesis,referred to as stone powder)or ore entrained mud powder(referred to as mud powder),and the subjective factors are more influential during the test operation.Therefore,it is important to reduce the subjective influence during the MB value test,to quantitatively analyze the percentage of mud powder in mechanism sand,and to study the influence of different powder contents on the amount of polycarboxylic acid water reducing agent admixture,so that the water reducing agent increase in mechanism sand with different mud powder contents can be studied.This thesis takes the different clay fractions,clay powder and water reducing agent as the basis for the study.In this thesis,the intelligent detection system of methylene blue value of mechanism sand is designed based on MATLAB programming platform,HSV image space and computer vision,which not only has the advantage of intelligent testing process,but also has high accuracy of judgment based on computer vision of methylene blue detection system and can identify more accurately.The MB value test,expansion capacity test and hydration exotherm test were carried out for different clay components and stone powder,and the results showed that the order of MB value adsorption was montmorillonite > mine clay powder > ilmenite > kaolinite >limestone powder,while the hydration exotherm test results showed that the hydration exotherm rate(in order of powder type)of cement containing different powders without polycarboxylic acid water reducing agent was Montmorillonite > kaolinite > ilmenite >limestone powder > mine clay powder,but after the water reducing agent was added,the hydration exothermic rate of its components basically decreased simultaneously during the test period,and the exothermic rate was also lower than that of the test group without water reducing agent.The results show that the adsorption of mud powder to polycarboxylic acid water reducing agent is very obvious,and within the suitable dosing range,the admixture of stone powder plays a certain enhancement role in the strength of net slurry;while the admixture of mud powder will reduce the strength of net slurry,and when the content of mud powder is more,the improvement effect of additional water reducing agent on the flowability and strength of net slurry is limited.According to the results of MB value test of mechanism sand,SSA-Elman neural network models for presumption of mud powder and stone powder content were constructed respectively,and the results showed that the presumption accuracy of mud powder content was significantly greater than that of stone powder,so the presumption model of mud powder content was chosen.The APP based on MATLAB was designed,and the model of water-reducing agent was established through the net slurry test of water-reducing agent with different percentages of powder,and the applicability of the model of water-reducing agent was verified in mortar and concrete tests,and the results showed that the applicability of the model was better for mortar than concrete.