T05872020Method for Mixing and Consistency Testing of Cement Mortar

1Purpose, scope of application, and reference standards

This method specifies the test method for mixing and consistency of cement mortar

This method is applicable to cement mortar and other materials using this method,The consistency test is suitable for consistency less than120mmThe mortar.

Reference standards

Code for Testing Aggregates in Highway EngineeringJTGE42

Experimental mortar mixerJGT3033

2Instruments and materials

21Mortar mixer:Should comply with the current "Test Mortar Mixer"JGT3033The public

22Sand slurry viscosity meter:Composed of three parts: test cone, cone cone, and support,As shown in the figureT05871As shown. The height of the test cone is145mmThe diameter of the cone bottom is75mm,The mass of the test cone and sliding rod should be3002g:The conical tube is a closed cone made of steel plate,The height of the cylinder is10mThe inner diameter of the upper opening of the cone push tube is150mThe volume is10The support is divided into three parts: base, bracket, and dial,Made of cast iron, steel, and other metals.

23Steel rammer:diameter10m, Long for350m,The end is hemispherical.

24Stopwatch and other auxiliary tools.

3Test preparation

3.1The temperature inside the laboratory should be controlled within20℃5℃,Relative humidity not less than50%The raw materials for mortar mixing should be placed in the laboratory at least24h

3.2Sand should pass95mmThe square hole sieve,475mmThe sieve residue on the sieve shall not exceed10%,And the sand material should be stirred evenly;Cement and admixtures are not allowed to have clumps,Apply before use09mmsift

33The sand material should be in a dry state,Moisture content not exceeding0.2%,Moisture content shall be in accordance with the current "Code for Testing Aggregates in Highway Engineering"JTGE42Determine according to the regulations

34The amount of materials used is measured by quality. Quantify precision:Cement and admixtures, water and additives are05%Sand as a scholar%

4Mortar mixing

41Clean the mortar mixing pot thoroughly,And keep the pot moist;According to the mix proportion,Mix first, no less than30%Mortar with the same capacity and proportioning,Hang slurry on the inner wall of the mixer,Unload the remaining material

42Pour the weighed sand, water, cement, and additives into the machine in sequence,Start the mixer immediately,The mixing time should not be less than1208Mortar mixed with admixtures and additives,The mixing time should not be less than1808.-The amount of secondary mixing should not be less than the capacity of the mixer30%,Should not exceed the capacity of the mixer70%.

5Experimental steps

5.1This method should be followed4Prepare mortar.

52Wipe the surface of the cone and the test cone clean with a damp cloth,Gently wipe the sliding rod with a small amount of lubricating oil,Then wipe off the excess oil on the sliding rod with absorbent paper,Enable the sliding rod to slide freely

53Load the mortar mixture into a conical cylinder at once,Make the mortar surface lower than the cone mouth by about10mm左右,Insert a pestle from the center of the conical cylinder towards the edge for tamping25time,Then use a wooden hammer to gently tap on four different parts of the cone that are roughly equidistant from each other5~6time,Make the mortar surface flat,Then place the cone tube on the base of the mortar consistency meter

54Adjust the fixing bolt of the trial cone sliding rod,Slowly move the sliding rod downwards,When testing the coneTighten the fixing screws when first in contact with the mortar surface,Make the lower end of the rack measuring rod just touch the upper end of the sliding rod,Read the reading on the dial.(Accurate to1mn)

55Unscrew the fixing bolt,Simultaneous timing,10sImmediately tighten the fixing screws afterwards,Contact the lower end of the rack measuring rod with the upper end of the sliding rod,Read five from the dial1TheHandHThe difference,It is the consistency value of mortar,Accurate tom

5.6The consistency of the mortar inside the conical tube is only allowed to be measured once,When conducting repeated measurements,Should be resampled

6result processing

Take the arithmetic mean of two parallel test measurements as the test result,Accurate to1mm:If the difference between two measurements is greater than10mm,Then retest

7Test Report

The test report should include the following contents

(1)Name of the required testing item

(2)Variety, specifications, and place of origin of raw materials

(3)Test date and time

(4)Name, model and number of the instrument and equipment

(5)Environmental temperature and humidity

(6)execution standard

(7)Mortar mix ratio, mortar consistency

(8)Other content to be explained

provisions explanation

This method refers to the "Standard Test Method for Basic Performance of Building Mortar"(G70-2009)(Hereinafter referred to as the "Filial Piety Standards")The application of Guodong slurry in highway engineering retaining walls, slopes and other engineering parts is widely used,Therefore, the dynamic slurry test method has been added. The difference from the reference standard lies in,Mixing sand,Choose a dry state,Restrictions have been imposed on the open to dry state:Moisture content ≤0.2%,The reference standard uses sand as the saturated surface dry,The saturation surface is affected by the content of seconds, and there is a significant color noise,And not easy to operate,Due to the aforementioned country of origin,The raw materials for vegetables and mixed soil will be adjusted from a sand state to a dry state