News

First, Design the Concrete Mixture for Hot Climates
Many factors must be determined before pouring in hot climates, and pouring problems in hot weather must be minimized.
Before that, prepare the concrete components and plan the pouring and curing processes, in addition to the required workability and strength.

First, Requirements for Fresh Concrete
1- Slump must not be less than 10 cm under normal conditions, as concrete less than that is difficult to transport and pour.
2- When designing, slump must be determined directly upon pouring, not during mixing.
3- When making mixes Confirmation in the laboratory: Site conditions must be taken into account to determine slump and stress.
Second: Requirements for Hardened Concrete
1- The effect of curing on the concrete must be taken into account, and the optimal curing method must be determined based on available capabilities. 2- Determine the maximum water-to-cement ratio to achieve the required strength and limit shrinkage.
General Considerations in Mixture Design
1- The concrete mixture must be designed using one of the known methods, and the maximum water-to-cement ratio must be determined. 2- To limit temperature rise, the lowest possible cement content must be used while maintaining stress and durability. 3- After design, the design must be verified in the laboratory, determining slump and slump losses, determining initial and final setting times, and ensuring that the required slump has been achieved on-site. 4- Mixes must be prepared in the laboratory, and the effect of using high doses of Type F on-site must be studied.
Design Special Concrete Mixes As we mentioned previously, concrete is exposed to problems in hot areas, such as loss of mixing water, drying cracks, and shrinkage. and so on. In some special and sensitive facilities, these problems must be reduced, so these mixtures are called special mixtures. How can shrinkage be reduced...?
Polypropylene fibers, steel fibers, or silica fume and fly ash can be used.
First, the use of fibers. Polypropylene fibers are the most common type for these cases. They are determined according to the product data sheet. Of course, they require additional doses of additives or mixing water, taking into account the maximum ratio to avoid the expected loss on-site due to the fibers. By the way, Polypropylene fibers reduce compressive strength by about 5%, while steel fibers improve strength by about 10%.
Second, the use of silica fume and fly ash fly ash
These materials limit shrinkage by limiting the rise in temperature. They are added to the mixture in one of two ways: A - Either they are added as a percentage of the cement. B - Either they are added to replace part of the cement content (fixed weight of cementitious materials). When calculating the water content, the addition of these materials to the cementitious materials must be taken into account. How can slump loss be assessed using a standard method? The first method: After determining the appropriate quantities for the mixture: The concrete is mixed for about three minutes, then stopped for three minutes. Then, mix again for two minutes. The slump is determined as the initial slump. Mixing continues for 15 minutes, and the slump is determined. This slump corresponds to the slump determined during pouring, which is 45 minutes.
The second method
Mix quantities are prepared. The concrete is mixed for about 3 minutes, then mixing is stopped for 3 minutes, then repeated for 2 minutes, and then the initial slump is determined. Mixing is stopped, and the mixture is covered with wet burlap. After 20 minutes, mixing is repeated, and an appropriate amount of water is added (the total does not exceed the maximum amount). The slump is then established. During the actual pouring process, all the water in the station must be added.

It's a type of adhesive whose main component is cement and some carefully selected chemical compounds to achieve a set of advantages, such as strong adhesion, high pressure resistance, and impermeability to water. Therefore, it's recommended for use in bathrooms and kitchens exposed to constant water. Its most important feature is its convenient workability, which makes adhesion easier for craftsmen. It also allows for a suitable working time.
This material is also used to bond marble weighing between 70 and 90 kilograms.
Not only that, it's suitable for all types of surfaces, including plaster, brick, lightweight brick, gypsum board, and more. It can also be used on floors, both indoors and outdoors.
It's available in gray and white.

So, what else makes it special?

• What makes it special and faster and more durable than regular mortar is its
• Suitable for use in Middle Eastern climates.
• Can be used in completely submerged areas.
• Flexible, therefore resistant to surface vibrations.
• Can be used indoors and outdoors.
• Resistant to bleed-through and slip-resistance.
• High adhesion strength.
• Easy to use with a good set-up time (20 minutes at 35°C).
• Water and moisture resistant.
• Suitable for installations with thicknesses from 2 mm to 8 mm.

Standard Specifications:
Complies with DIN 18156, BS 5980 Class A Type 1, ASTM C 348, ASTM C 349, ANSI 118.4 and exceeds European C1 & C2 (EN 12004) Standards).
Instructions for Use:

Surface Preparation:

• All surfaces must be clean and free of any impurities, oil, dust, grease, mortar residue, or any foreign materials.
• A primer coat must be applied using Tiba Seal (clear or white) on difficult surfaces such as gypsum and wood surfaces, etc.
• If the surface is dry, moisten it with water, taking care not to over-water before starting work.
• Tiles must be clean and free of any contaminants on their surfaces.

Mixing:
Mix one 25 kg bag of cement adhesive with 5 – 6.25 liters of water by gradually pouring the contents of the bag into the water while stirring. A slow mixer (approximately 300 rpm) can be used to mix the product. Continue mixing for three minutes, then let the mixture stand for ten minutes, then mix again for two minutes until a homogeneous, clump-free mixture is obtained.
Application: Apply the ceramic adhesive to the surface using a combed trowel to achieve the appropriate thickness. Spread the mortar over an area no larger than 1 square meter. Adhere the tiles to the surface filled with mortar, pressing them down firmly, ensuring that the mortar does not slide off the sides of the tiles. Check the tiles to ensure they are filled with mortar by periodically pulling one of the tiles out and reattaching it. Remove excess mortar from the surface of the tiles using a cloth. /> The tools used should be cleaned with water, and if the material dries, it is automatically removed.
Preventive Measures:
The material should be spread on the surface in an area that allows the tiles to be installed within a period not exceeding 15 minutes of application at a temperature of 20°C. A surface crust forms on the surface of the mortar, preventing the tiles from adhering to the spread Tiba Ceramica 400 mortar. The tiles should be installed during the operating period of the cement adhesive mortar. A primer layer should be applied using Tiba Seal (clear or white) on porous surfaces such as gypsum and wood. Joins between tiles should be filled within 3 – 8 hours of tile installation (depending on site conditions) using City Grout (fine or coarse), depending on the joint width. Do not apply to metal surfaces. Plastic spacers should be used to determine the joint width between tiles, depending on the type and style of tiles.
Consumption:
3 – 7 kg/m² Depending on the nature of the surface and the type of mortar used.

Cleanliness:
All tools used must be cleaned with clean water immediately after use.
Dry parts can be removed mechanically.
Packaging: Available in 25 kg bags.
Storage and Shelf Life: 12 months in dry, shaded storage in tightly sealed bags.
This material is Taiba Ceramica 400. You can order it online from the company's website.
You can request a data sheet with all the details.

First, what is a hot climate?
It is a climate where daytime temperatures in the summer reach 30 degrees Celsius or more, and it is located in the Northern Hemisphere between latitudes 15 and 30 north.
Hot climates are divided into three categories:
1- Hot and dry climates
2- Extremely hot and dry climates
3- Hot and humid climates
First, an extremely hot and dry climate is when the difference between minimum and maximum temperatures is greater than 20 degrees Celsius, and the humidity during the summer is less than 30%.
This includes the governorates of Aswan, Qena, Assiut, and the oases.
The rate of evaporation in concrete per hour is greater than 1 kg per square meter.

Second, hot climates

The difference between the maximum and minimum temperature is less than 20 degrees Celsius.
Relative humidity is from 30 to 70%.
Includes the governorates of the Middle Delta, Cairo, and the cities of northern Upper Egypt.
The evaporation rate in concrete is approximately 1 liter per square meter per hour.
Humid climate.
The difference between the maximum and minimum temperature is less than 10 degrees.
Relative humidity is greater than 70%.
Includes the governorates of the Mediterranean coast, the Red Sea coast, and South Sinai.
The evaporation rate in concrete is less than 1 liter of water per square meter per hour.

What is relative humidity?

It is the ratio between the water vapor pressure and the saturated water vapor pressure at the same temperature. It expresses the ability of the air in contact with the concrete surface to Water vapor carrying capacity. The lower the relative humidity, the greater the air's ability to carry water vapor. So, what is the evaporation rate in concrete? It is the weight of water evaporated per unit area per unit time (kg/m²/h).

The evaporation rate depends on the following:
1- The difference between dry and humid air temperatures. 2- Relative humidity. 3- Air speed and direction. 4- Solar radiation. 5- Concrete surface temperature. Evaporation at the concrete surface goes through three basic stages.

The first stage: This is the stage immediately after pouring the concrete, where the water rises to the top, forming a thin film known as bleeding. The evaporation rate in this stage is the same as the evaporation rate of water under the same conditions. The water continues to rise until it evaporates. Initial Setting

Stage Two
This stage begins immediately after initial setting. It occurs when the evaporation rate is higher than the permeation rate (when uncured). It is accompanied by the appearance of white spots on the concrete surface. This stage continues until the concrete surface becomes dry. This stage is called surface hardening. During this stage, the concrete temperature rises and is capable of converting free water into steam, which rises to the top of the concrete and then evaporates.

Stage Three
This stage begins later when the water level in the concrete falls below the exposed surface to a distance that stops the evaporation rate. What are the main problems of concrete production in hot climates? Shrinkage Cracks Concrete is negatively affected by high temperatures during pouring, the most important of which are: Decreased resistance, elasticity parameters, porosity, increased volumetric changes, and increased durability over time.

/> First, regarding fresh concrete
1- Increasing the dryness of the concrete consistency and consequently decreasing slump for the same components, which requires increasing the water content, which reduces resistance and increases porosity. 2- Increasing the rate of slump loss. This is concrete that is difficult to pour and compact (with the same ingredients, even the additions). 3- Hot weather accelerates the setting of cement and hardening of concrete, making it difficult to transport it over longer distances and finish its surface. 4- The increased likelihood of drying shrinkage cracks appears as a result of the rate of water evaporation exceeding the rate of permeation. This appears on large surfaces and also depends on relative humidity, as it is almost invisible at humidity levels above 80%. 5- If temperature, low humidity, and wind speed combine, plastic shrinkage will occur. 6- Difficulty controlling the proportion of entrapped air. 7- All of these problems are compounded when pouring concrete with a high cement content and a low water-to-cement ratio, as the temperature increases the heat of hydration. Second: The Effect of Concrete Temperature on Hardened Concrete 1- Decreased Strength Pressure despite increased resistance at early ages due to higher ambient temperature. 2- Decrease in elasticity after 28 days and subsequent ages. 3- Increased drying shrinkage and increased likelihood of cracking. 4- Failure to take necessary precautions in high-strength concrete leads to disastrous results in reduced resistance, cracking, etc.

Effect of temperature on mixing water
High water temperature leads to higher concrete temperature. A 10-degree increase in temperature above the normal range leads to a decrease in slump of approximately 3 cm. Use of reducing additives in mixing water. Exceeding the normal rate, which increases the cost. The specific heat of water ranges from 4 to 5 times the specific heat of the aggregate, so water temperature has the greatest impact on concrete temperature.

Effect of temperature on admixtures
1- High temperatures significantly affect the performance of admixtures. 2- The effect of retarding admixtures is significantly reduced. 3- Increased slump loss. 4- The harmful effects of improper storage are increased.