The point load of masonry mortar is measured by a tester

The point load of masonry mortar is measured by a tester

Overview:

This product is developed and produced in accordance with GB/T50315-2000<<Technical Specification for On site Inspection of Masonry Engineering>> It is a specialized instrument for testing the strength of masonry mortar. Its characteristic is that it can be directly tested on site or in the laboratory, without affecting the stress performance of the wall. It has the characteristics of easy detection, convenient operation, short required time, and high testing accuracy. It can meet the objective needs of quality control of masonry engineering sites and the identification and evaluation of the quality of old and ancient houses

Technical Specifications:
■ Maximum range: 3KN
■ Maximum travel 30mm
Net weight 4.8kg
■ Power supply voltage: 6V

Usage:
Before using the instrument, first connect the sensor to the microcomputer peak display, then turn on the power and turn on the power switch on the display. At this time, the "load" indicator light will turn on. Observe whether the number on the display is zero. If not, press the "zero" button to reset it to zero
Press the "peak" button, the peak indicator light will turn on, and the load can be added. When the specimen is damaged, the display will show the maximum strength value of the specimen, in N
When using it as the next specimen, press the "peak" button to turn on the loading indicator light, and the previous test data will be eliminated. If the value displayed on the monitor is zero (small numerical drift on the monitor is normal), press the "peak" button again to turn on the "peak" indicator light. At this time, the next test can be loaded. If the value displayed on the monitor is large, press the "zero" button while the "loading" light is on to reset it to zero The above procedure needs to be repeated for each experiment, but when the peak indicator light is not on, the display does not have peak protection function, and the displayed value will automatically disappear with unloading
Process (or select) the large pieces of mortar peeled off from each measuring point into test specimens that meet the following requirements: thickness 5-20mm, estimated radius of action 15-25mm, the large surface should be flat, but the edges are not required to be very regular
Draw the action point on the mortar specimen and measure its thickness t with a caliper, accurate to 0.1mm
Place the mortar sample on the lower loading head, align the upper and lower loading heads with the pre drawn action points, slowly rotate the handle of the point load gauge clockwise by hand, and use the worm gear and worm drive to move the lifting screw downwards. When the loading head rests on the mortar sample, a pressure load is generated, and then the load is slowly and evenly applied until the specimen is destroyed, at which point the loading is stopped
After recording the peak display reading, substitute it into the formula to calculate the intensity. The reading unit of the point load gauge display is N
Assemble the damaged specimen into its original shape, and measure the shortest distance from the center of the actual load point to the edge of the specimen as the action radius, accurate to 0.1mm
Attention: Do not directly press the upper and lower loading heads. If the upper and lower loading heads are needed for this inspection, a mortar sheet must be placed between them to avoid damaging the loading heads
Calibration and adjustment of instruments
This instrument has been calibrated with a standard before leaving the factory When the sensor needs to be recalibrated after a period of use, the user can remove the four fixing screws on the back cover of the monitor, take off the front panel, and rotate the screw on the potentiometer in the lower left corner (top) of the digital display block The potentiometer below is used to adjust the zero point. When adjusting, the display should be displayed
The indicator is in the "loading" light on state for repeated loading and unloading tests After verification, seal the adjustment screw tightly with thick paint to prevent changes caused by vibration

Structure and principle:
The point load gauge consists of a worm gear and worm mechanical loading system, a pressure sensor, and a microcomputer peak display. The sensor is installed on the base of the loading system, and the peak display and the loading system are connected by wires When working, place the pre taken mortar sample on the pressure head and slowly rotate the handle of the point load gauge clockwise by hand to move the lifting screw downwards. When the loading head rests on the mortar sample, a pressure load is generated, and then the load is slowly and evenly applied until the specimen is destroyed. At this time, the microcomputer peak display will maintain the maximum load.

Maintenance and upkeep:
The microcomputer peak display adopts integrated circuit assembly, and the power supply voltage should be stable within the range of 220V ± 5V during use
After using the instrument, it should be cleaned and stored in a box for future use
The worm gear box should be regularly filled with yellow dry oil to maintain lubrication
The instrument should be used and stored indoors in a dry place, avoiding direct sunlight, rain, and moisture to extend its service life

The point load of masonry mortar is measured by a tester