The deterioration of the polycarboxylate superplasticizer PCE liquid water reducer is indicated by the following most obvious sign: abnormal appearance.
During summer, when the temperature is high and the humidity is high, the polycarboxylate superplasticizer PCE liquid water reducer that has been added with retardants (such as sodium gluconate and sucrose) is most likely to "change its behavior", especially in the following situations, one should be particularly vigilant:
✅ 1. After stratification and prolonged sedimentation, some of the decanted water clear, while the lower layer forms a thick, sticky gel-like substance - this is mostly due to the hydrolysis of polyacrylate molecules or their reaction with calcium ions, resulting in precipitation.
Some iron cans containing the polycarboxylate superplasticizer PCE liquid water reducer also show rust-colored or black flocculent substances, indicating that metal ions catalyzed the reaction and oxidized!
✅ 2. The color of polycarboxylate superplasticizer PCE liquid has darkened, the admixture which was originally a light yellow transparent liquid, suddenly turned into yellowish-brown, orange-red, or even black and cloudy?
It is very likely that it has oxidized or bacteria have grown. Shine a flashlight on it, and the turbidity is obvious. You can also see floating objects or suspended particles. Then you should be even more vigilant.
✅ 3. The odor is obvious. The odor of the normal polycarboxylate superplasticizer PCE liquid reducing agent is not strong; it only has a slight chemical smell. Once you smell a pungent odor, an acidic or musty smell, it can be generally concluded that bacteria or fungi have begun to "settle down". Especially when the temperature exceeds 30℃, bacteria multiply rapidly, produce acid and gas, and the pH value of the admixture drops below 5, making the odor even more pronounced.
The three areas where concrete begins to show problems after the deterioration of the polycarboxylate superplasticizer PCE liquid water reducer
❌ 1. The reduction rate decreases after the deterioration of the polycarboxylate superplasticizer PCE liquid water reducer. The main chain structure is damaged, and the dispersing effect on the cement particles is weakened.
In simple terms:
**At the same dosage, the effect is greatly reduced!
** The freshly mixed concrete becomes increasingly dry, and the pump cannot be operated. It is necessary to add water on-site to thicken it.
❌ 2. The slump loss is rapid, especially for the polycarboxylate superplasticizer PCE liquid slump-retaining water reducer after deterioration. The slump drops by half directly within 30 minutes, and problems such as "pseudo-setting" and "rapid hardening" may occur.
Many people mistakenly think it is a problem with the cement, but in fact, the side chain structure of the polycarboxylate superplasticizer PCE liquid water reducer has been damaged, and the slump-retaining effect is completely lost.
❌ 3. The concrete strength is abnormal. The polycarboxylate superplasticizer PCE liquid water reducer introduces metal impurities and microbial metabolic products, which interfere with the cement hydration.
The early strength drops severely. The compressive strength test at 3 days and 7 days fails directly, and problems such as segregation, bleeding, and cracking may occur. The construction site becomes chaotic immediately.
Practical! Just look, smell and shake of The polycarboxylate superplasticizer PCE liquid
Quickly determine if the polycarboxylate superplasticizer PCE liquid water reducer has deteriorated. Don't wait until the concrete has problems before suspecting the polycarboxylate superplasticizer PCE liquid water reducer. The following three steps can help you quickly check:
🔍 Step 1: Check if there is any sediment in the appearance? Has the color changed? Has there been any stratification?
Shake it, let it stand and see if it re-stratifies or has suspended substances.??
👃 Step 2: Smell if there is any pungent smell? Sour smell? Moldy smell? If so, it is basically contaminated by microorganisms!
🧪Step 3: Conduct a small test by using a small amount of the polycarboxylate superplasticizer PCE liquid water reducer to do a slump flow test for a clean mixture, or mix a small amount of concrete and observe the slump, maintaining strength and setting time.
Units with conditions can send it for testing of core indicators such as pH, metal ions, microbial content, and water reduction rate.
Correct storage recommendations for polycarboxylate superplasticizer PCE Liquid(please strictly follow)
✅ Storage recommendations of the polycarboxylate superplasticizer PCE liquid water reducer are as follows:
- **Storage temperature:** Keep below 25℃
- **Container selection: **Use stainless steel or polyethylene materials. Do not use iron cans or carbon steel barrels.
- **Store in a dark place and seal to prevent UV radiation from causing degradation.
- **Add preservatives (such as 0.1-0.3% carbosan) to enhance antibacterial ability.
- ** The shelf life should not exceed 6 months. Especially in summer, it is recommended to rotate usage in advance
❗Reminder: Minor stratification can be repaired by heating and stirring. However, if there is an unpleasant smell, sedimentation, or significant performance decline, it must be discarded immediately. Do not take the risk of using it!