Product Information

Standard construction process of JOINTACE JA-40

Step Process Application details
Pouring concrete and initial finishing Level the surface Fresh concrete is poured and carefully compacted using a vibrator as usual. Then, the surface of the concrete is leveled using a wood trowel, etc. If you select 2 or 3 in the next step to remove the bleed water, a slope or drainage pit should be formed at the concrete surface.

<Cautions>: Because a steel trowel may decrease the JOINTACE penetration, it should not be used.
Preparation of JOINTACE Removal of bleed water The bleed water should be properly removed, with no scum and bubbles remaining on the surface. (These become performance deterioration factors. Bleed water dilutes the sprayed JOINTACE or causes it to run off. Scum and bubbles may decrease the penetration of JOINTACE into the surface.) One of the following removal methods should be selected, considering the pouring scale and amount of bleed water.
  1. Direct removal by absorption using cloth, sponge, etc.
  2. Bleed water is collected and drained along the slope formed on the surface. The bleed water is drained by using a pump or through a hole in the formwork.
  3. Some drainage pits are installed with a pump system. These drainage pits have a structure that can be easily cleaned. When garbage and rusty water accumulate, these must be cleaned up before the next section of concrete can be poured.
Because it is applied to the surface of concrete with a smooth finish, the shear strength of a construction joint that is prepared with JOINTACE tends to decrease. The application to plain concrete that does not need to protect the reinforcement from rusting has not been recommended. If greater shear strength is required, a notched trowel (with about 5 mm teeth) can simply be used to provide a skid resistant surface. (If the reinforcement is overcrowded, it might be difficult to make the surface rough. However, only a portion of the concrete cover should be rough.)

If bleed water collects on the rough surface, it should be carefully removed.
The drained bleed water must be treated in accordance with the law, etc.
Application of JOINTACE (1) Timing Spraying can commence when the concrete bleed water on the surface begins to dry.
Measuring The poured concrete should be suitably classified considering its workability and the following process. Spraying work is performed for each classification. (To prevent the deflection of the spray, it is desirable to divide the work area into approximately 10 m2 sections.) JOINTACE is applied as an undiluted solution. A fluid volume corresponding to each section should be measured and poured into the spraying equipment. JOINTACE comes in 18-kg cans, each of which is sufficient for treating about 60 m2 of concrete.
Spray (1) The application of JOINTACE should be uniform, with approximately 300 g applied per square meter. If a slope has been installed on the surface, the spraying should be divided into several steps to prevent any overflow. In order to obtain a stable unification performance from the construction joint, the concrete cover should be carefully treated.

<Equipment for spraying>
Commercial equipment can be chosen according to the scale of the job and would include a sprinkling can or sprayer (hand-type, pressure-type, or backpack power–type).

In rainy weather, JOINTACE spraying is done with preventive measures against the rain. Otherwise, the spray runs off with the rainwater.
Step Process Application details
Application of JOINTACE (2) Spray (2)
  • Treatment can be difficult when the reinforcement bars are overcrowded. Spraying can be performed by using a long nozzle to reach the area.
  • The nozzle should be immersed in water when not spraying to prevent the JOINTACE from drying and clogging the nozzle.
  • When using equipment with a large spraying mouth (sprinkling can, etc.), the spraying deviation tends to become large, requiring careful application.
  • When the concrete mixture contains a large proportion of cement, as is the case with high-strength concrete and fly ash concrete, JOINTACE tends to penetrate downward. Tapping on the surface make the penetration easy with a brush.
  • The leveling can be difficult in an area where the reinforcement bars are overcrowded. In this case, the spraying should be divided into several steps to prevent the uneven distribution of JOINTACE.
Curing Curing the treated surface After the JOINTACE is sprayed and 30–60 min have passed, any JOINTACE remaining on the surface should be removed by absorbing with a cloth, etc.(If simply left alone, it will form a resin film, which will deteriorate the quality of the construction joint. Once this film forms, it will be difficult to remove. So remove as much as possible at this stage.) Because freshly applied JOINTACE can be washed off by rainwater, preventive measures such as covering with a sheet should be taken. After the surface has been completely treated with JOINTACE, the usual water spray curing can be done for the concrete. (The end point of treatment can be checked with the water-dropping method. In this method, clean water is dropped on a concrete surface that has been sprayed with JOINTACE. If the water drops do not become cloudy, the treatment is completed.) After checking, it will be possible to move into the work area and perform the usual work.
Construction situation check Inspection The treated surface should be checked before the next section of concrete is poured. The condition of the surface should be inspected with reference to the following standard.

·GOOD: Because the JOINTACE will form a clear film after the treatment is completed, it becomes impossible to distinguish the difference between a concrete surface that has been sprayed and one that has not. (If this is required, a determination is possible using the following methods. 1. Compare the amounts obtained by scraping the surface of the concrete samples with a wire brush. 2. Determine whether a water drop penetrates the surface of the concrete sample.)
·BAD: The turbid resin film that contains laitance is on the surface. A large area of the surface is coved with this resin film.
Disposal when bad Unfortunately, when a resin film is confirmed on the surface, it must be removed by using shot blasting, etc. Re-spraying with JOINTACE or laitance removal is performed as a repair.
Pouring new concrete Pouring interval The pouring interval between the next fresh section of concrete to be poured and the previous hardened concrete should be greater than 24 h when the temperature is 20 °C(In a long period of time, it is confirmed by four months.)
Preparation for pouring Cleaning and wetting proceed as usual. The water that remains on the surface is carefully removed.
Pouring concrete As usual, the concrete should be compacted properly to avoid segregation so that no honeycombing forms in the concrete.

Disclaimer: The information herein is subject to change without notice. The information presented herein is true and accurate to the best of our knowledge, but without any guarantee unless explicitly given. Since the condition of use is beyond our control, we disclaim any liability, including for patent infringement, incurred in connection with use of these products, data or suggestions. Buyers must determine for himself, by preliminary tests, or the suitability of these products for his purposes. Careful precautions are required in handling all chemical products. Please refer to our MSDS

Detail : JOINTACE JA-40