Cement Testing Equipments

INTRODUCTION

 

The strength of concrete is generally estimated after 28 days by crushing field test cubes or cylinders made from the representative concrete used for the structure. The utility of ascertaining strength after 28 days is often questioned since by this time considerable concrete would have been placed and work may have progressed. It is then rather too late for remedial measures. It is therefore of tremendous advantage to predict 28 days strength within a few hours of casting the concrete so that, we have a good idea about the strength of the concrete.

The rate of gain of strength of concrete depends on the reaction rate of cement and additions with water (Hydration). In common with all chemical reactions, the rate of reaction depends on reaction of temp. Higher reaction temperature gives higher rate of reaction e.g. the concrete gains strength more rapidly when its temp. is higher. Accelerated curing is the process by which the temperature of the concrete is raised artificially by applying external heat to speed up the rate of gain in strength.

 

The test method covers procedures for curing test specimens of concrete stored under conditions intended to accelerate the development of strength. The procedures are: Procedure A- Warm Water Method, Procedure B-Boiling Water Method

 

GENERAL DESCRIPTION AND SPECIFICATIONS

 

Accelerated Curing Tank having capacity to accommodate 6/12/18 Concrete Cubes of 150mm size with a facility for accelerated curing by Boiling water method up to temperature range : 100 +/- 2 deg.C as per IS standard IS : 9013.  Also it will have capacity for curing by warm water method at temperature 55 +/- 2 deg.C

 

Tank will consist of a rectangular double walled metal cabinet, inside lined with stainless steel, outer powder coated. Easily replaceable high Wattage heaters are mounted in side the chamber. A slow speed stirrer is provided to circulate water inside the chamber to maintain the uniform temperature of water.  A strong stainless steel perforated platform is provided for keeping the cubes and also have a lid with lifting handle to cover the chamber.

 

The temperature is indicated and controlled by a DIGITAL auto tuning PID Temp. Controller with soak timer to control the duration of heating and then to shut down the system without manual attendance. The front panel will have power supply indicating lamp, control action indication lamp and one main switch. Suitable for operation on 220 V, 50 Hz single phase, AC supply or 440 V 50 Hz, three phase AC supply, for bigger size of curing tank.

 

OPTIONAL ACCESSORIES : Rubber hand Gloves. Spare Heaters. Low water Level cut off device to safeguard heaters against low water level burn out In built refrigeration system for curing at 27 deg C

 

ALSO AVAILABLE

 

ACCELERATED CURING AUTOCLAVE : BY STEAM PRESSURE

ACCELERATED CURING DRIER : BY DRY HEAT

Consists of a frame mounted on coil spring to carry the cube mold and a revolving shaft provided with an eccentric. By means of a balance weight beneath the base plate attached rigidly to the frame, the center of gravity of the whole machine, including the cube and mold,is brought either to the eccentric shaft or within a distance of 25 mm below it. Normal running speed of eccentric shaft is 12000 + 400 RPM. Fitted with belt guard. The motor driven by an endless belt running on a crowned pulley on the vibrating machine. Supplied complete with one cube mold of 7. 06 CMS with base plate. Suitable for operation on 230V single phase AC supply. With time switch. Relevant standard : is : 4031

è    MANUALLY OPERATED

è    MOTORISED OPERATED

 

Manually operated 0-500 Kg. Complete with one briquette mould and set of weights to weigh 50, 100, 150 and 200 kg. without lead shot.

 

Motorised Operated  0-900 Kg. The instrument employs of friction free, accurate, double, lever system, the load being applied by means sliding weight on the top lever  The capacity of the unit is 900 kgs. After fixing the briquette in the jaws, the machine is swithched on. The sliding weights slides over the calibrated lever thus applying tension to the specimen. A micron-Switch fitted instantly stops the machine on failure of the briquette and on failure the tensile load is accurately read to 0.5 Kg by means of a marker provided on the sliding weight. The machine can be made operationable for subsequent test only after bringing the sliding the weight to its zero position. Suitable for operation on 230 volts, 50 cycles, single phase, A.C. supply. Complete with one brass briquette mould and one base plate.

It is used for mixing cement pastes, mortars and pozzolanas. The mixer consists of an epicyclic type stainless steel paddle imparting both planetary and revolving motion. Mixer have two speeds. Mixer blade has low speed of 140 + 5 rpm and medium speed of 285 + 10 rpm, while it also has a planetary movement of 62 + 5 rpm in low range and planetary movement of 125 + 10 rpm in medium range. Stainless steel bowl fitted with handle, fitted with lid made of non-absorbing material and not attacked by cement, masonry cement, cement pozzolana mixture or lime pozzolana mixture. The scraper consists of semi rigid rubber blade attached to a handle about 150 mm long. The blade about 75 mm long, 50 mm wide and tapered to a thin edge. Suitable for operation on 230 Volts, single phase.

RELEVANT STANDARD : IS : 4031, IS : 1727

INTRODUCTION

 

Used to determine the amount of water required to produce a cement paste of standard consistency and the setting time. The time it takes for a cement to stiffen to a standard value after addition of water is commonly known as the set time. The test involves mixing cement with water and then measuring its resistance to penetration of a standard probe at varying intervals of time, until a certain value is reached.

 

GENERAL DESCRIPTION AND SPECIFICATIONS

 

Consist of a metallic frame bearing a movable rod with cap at one end.

The needles and plunger can be fixed centrally in to the rod by clamping screw. The movable rod carries an indicator which moves over a graduated scale attached to the frame. The scale is 40mm in length with the smallest division of 1mm. The dashpot facilitates the gentle lowering of the movable rod with needle.

 

The vicat mould can be in the form of frustum of a cone having 70 mm in dia at the base, 60 mm at the top and 40 mm high or split type. A non porous base plate of glass or metal also provided. Complete with consistency plunger, initial and final setting needles in a nice jewellary case.

 

RELEVANT STANDARD: IS: 5513-1976

 

OPTIONAL ACCESSORIES AND SPARES

 

*      SPARE VICAT MOULD CONE TYPE

*      VICAT MOULD SPLIT TYPE

*      SPARE SET OF NEEDLES.