The spread of the novel coronavirus is taking a direct hit on the operations of airlines in Asia. About 500,000 flights taking off and landing in mainland China have been canceled since January, according to aviation information company Cerium. Tourists and business trips have plummeted. On the booking website, there are a large number of air tickets for local routes with a price reduction of nearly 90% compared with the original price and only tens of yuan for a one-way trip.
In February, China's aviation industry recorded its largest single-month loss of 24.59 billion yuan, of which airlines lost 20.96 billion yuan.
Data from the Civil Aviation Administration of China showed that in February, the number of passengers traveling by air fell 84.5% year-on-year to 8.34 million.
The stagnation of the Asian aviation industry has brought volatility to foam concrete.
The common problems of foamed concrete are bubbling, cracking, collapse, shrinkage, and other phenomena. To treat these phenomena, the proper medicine can be found, and the cause can be effectively solved.
The main reason for the collapse of foamed cement is that the cement solidification speed is too slow. We can solve this situation from the following aspects
1. Add accelerator to improve the setting time of foamed cement
Accelerators are used in more and more concrete applications. Foamed cement has high requirements for accelerators. It is not just a fast setting but also needs to be adapted to the performance of foamed cement, and accelerators cannot be added. After affecting the foaming situation.
2 Add an early strength agent to improve the early strength of foamed cement and reduce the stress generated during the exothermic process of cement hydration. Only when these two forces are balanced can it be ensured that the foamed cement will not crack and collapse in the later stage.
3. An appropriate amount of sulfoaluminate cement can be added, which many manufacturers choose to use in winter, and the cost performance is still relatively high. However, this amount of addition should also be paid attention to. It should not be added blindly. After many customers add sulfoaluminate cement, the finished product becomes very brittle in the later stage, without toughness, low strength, and severe pulverization. So we still have to adjust according to the current situation.
4 The water-cement ratio is not suitable. Collapse, retraction, bleeding, insufficient strength. To a large extent, it has something to do with the inappropriate water-cement balance. The adjustment of the water-cement ratio is a technical activity that requires trial and error. It has a lot to do with the cement of foamed cement and the fly ash aggregate, and it needs to be practiced repeatedly according to the actual situation. In this, we can add a plasticizer to adjust the water-cement ratio. This effect is very immediate.
The above contents are some solutions summed up by Tongrun according to the reasons for the collapse of foamed cement. If you encounter other problems or reasonable solutions in the actual process, you are also welcome to communicate us.
Southern Copper Corp (SCCO.N) recently said its Peruvian mine remained closed after a six-week standoff with protesters and blamed the Peruvian government for failing to intervene in the safety of its 1,300 workers and their families.
The company said in a statement that a recent agreement to end protests at the Cuajone mine required the company to withdraw complaints against protest leaders because railways transporting minerals and supplies remained blocked. Production has been suspended since the end of February.
Peru's Energy Ministry said in a separate statement that it had also reached an agreement with Southern Copper to start talks to find common ground with local communities.
"If we shut down for a year, the government will stop receiving more than 3.1 billion soles ($830 million) in taxes and royalties, and 8,000 direct and indirect jobs will be lost. This is what we want to avoid, "Southern Copper added in the statement.
Peru has faced a wave of protests from indigenous communities, who accuse mining companies of not providing enough jobs and funding to poor local residents.
Central bank officials said last week that protests against copper mines such as MMG's Las Bambas and Southern Copper's Cuajone were dragging down the economy.
Peru is the world's second-largest copper producer and mining is an important source of tax revenue for the country. It is estimated that the supply and prices of the foam concrete will be influenced by that.
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