Mortar tensile bond strength test is completed on the electronic universal testing machine, also called mortar tensile testing machine. This paper will introduce the test method of mortar tensile bond strength.

1. Preparation of specimen

Preparation of 1.1 base cement mortar specimens

(1) raw material: cement: GB175 grade 42.5 cement; sand: JGJ52 medium sand; water: JGJ63 water standard.

(2) mixing ratio: cement: Sand: water =1:3:0.5 (mass ratio).

(3) molding: cement mortar made from the above mix ratio is poured into 70mm x 70mm x 20mm hard PVC or metal molds, vibratory molding or artificial molding according to 10.0.4.3 strip, and the inner wall of the test mold should be painted with water stripping agent in advance, waiting to be dry and spare.

(4) after molding 24h, the mold was released and placed in (23 + 2) centigrade water to maintain 6D, then placed more than 21d under test conditions. Before testing, use 200# sand paper or grindstone to grind the surface of the cement mortar specimen.

Preparation of 2.2 mortar slurry

(1) preparation of dry mixed slurry slurry

1) the samples to be inspected should be placed above 24h under test conditions.

2) the weight of water samples not less than 10kg should be weighed according to the manufacturer's ratio. If a range is given, the average value should be used.

3) put the sample to be placed in the mortar mixer, start the machine, add the specified amount of water slowly, and stir 3min to 5min. The mixed material should be used in 2H.

(2) preparation of wet mixed mortar slurry

1) the samples to be inspected should be placed above 24h under test conditions.

2) weighing products according to the proportion of manufacturers, and the total amount of dry materials is not less than 10kg.

3) put the ingredients into the mortar mixer, start the machine, add the specified amount of water slowly, and stir 3min to 5min. The mixed material should be used up within the specified time.

(3) preparation of mixed mortar slurry

1) the samples to be inspected should be placed above 24h under test conditions.

2) weighing the materials according to the mix ratio of the design requirements, and the total amount of dry materials is not less than 10kg.

3) put the ingredients into the mortar mixer, start the machine, add the specified amount of water slowly, and stir 3min to 5min. The mixed material should be used in 2H.

1.3 preparation of tensile bond strength specimen

The molding frame is placed on the forming surface of the cement mortar block prepared according to the 10.0.4.1 bar. The dry mixed mortar slurry prepared by 10.0.4.2 bar or the wet mixed mortar samples obtained directly from the site is poured into the molding frame, and 15 times are evenly inserted with the tamper, 5 times artificially, then 90 degrees, then 5 times, then the scraper is used in the 45 degree direction. Smooth the surface of the mortar and gently release it, and maintain it to the prescribed age at the temperature (23 + 2) and the relative humidity 60% ~ 80%.