Preparation and Characteristics of Light Foam Cement

2017 ◽  
Vol 727 ◽  
pp. 1029-1034
Author(s):  
Yan Zhang ◽  
Hui Chao Chu ◽  
Hui Li ◽  
Chun Yu Hua ◽  
Xian Jun Lyu

This present paper took ordinary Portland cement as main raw materials to prepare foam cement with properties, such as lightweight, high strength, and heat preservation, by the method of chemical foaming. The authors discussed the effects on the properties by key factors like water/cement ratio, foaming agents, foam stabilizers, accelerator and fibers of foam cement objects. Taken all the results show that in the condition that water/cement ratio of 0.48, foaming agents, foam stabilizers, accelerators and polypropylene fibers were adopted accounting for the quality of cement of 4.8%, 0.6%, 0.25% and 0.4% respectively, the characteristics of prepared formed cement samples could conform to the requirement of standard of JC/T266 formed cement.

2021 ◽  
Vol 4 (2) ◽  
pp. 16
Author(s):  
Honghong Ye ◽  
Delin Zeng ◽  
Yong Yang ◽  
Xingbo Fan ◽  
Wei Wang ◽  
...  

Considering actual construction conditions of Binchuan-Heqing Highway, this paper provides the C50 mix ratio conforming to engineering requirements by strictly controlling the quality of raw materials, optimizing the design of mix ratio scientifically, preparing superior C50 concrete 0 with manufactured sand, and optimizing the concrete mix ratio based on the adjustment of fly ash replacement, water-cement ratio, polycarboxylate-type water reducer mixing amount, sand ratio, etc. The result indicates that, the water-cement ratio has a great influence on the concrete strength, and if the ratio of coal ash is high in the binding material, the early compressive strength of the concrete will increase slowly.


2014 ◽  
Vol 908 ◽  
pp. 30-33
Author(s):  
Ping Tan ◽  
Yan Min Zhao ◽  
Qiu Hong Meng

The durability of high performance concrete is the main index of design. design.With the high durability, the high volume stability,the high compressive strength and the good workability, high performance concrete widely used in high-rise buildings, large-span Bridges, offshore in the construction of buildings, roads, etc.This paper prepared with different water/cement ratio of high performance concrete and tested the concrete workability, mechanical properties, durability.High performance concrete need preparate with low water/cement ratio, choose high quality raw materials,adding a sufficient number of mineral admixtures and high-performance admixture. Useing the high strength and high performance concrete can decrease the size of cross section, lose weight, gain greater economic benefits.


2013 ◽  
Vol 850-851 ◽  
pp. 847-850 ◽  
Author(s):  
Lin Chao Dai

In order to study the coal and gas outburst similar simulation experiment, coal similar material was made up based on the similarity theory. Based on the previous similar material study, the cement, sand, water, activated carbon and coal powder was selected as the raw material of similar material. Meanwhile similar material matching program with 5 factors and 6 levels was designed by using Uniform Design Method. And the physical and mechanical properties of the similar material compressive strength was measured under different proportions circumstances. The relationship between similar material and the raw materials was analyzed. The results show that choosing different materials can compound different similar materials with different requirements. And the water-cement ratio plays a decisive influence on the compressive strength of similar material. The compressive strength of similar material decreases linearly when the water-cement ratio increases.


2013 ◽  
Vol 6 (1) ◽  
pp. 50-61
Author(s):  
Amer M. Ibrahem ◽  
Shakir A. Al-Mishhadani ◽  
Zeinab H.Naji

This investigation aimed to study the effect of nano metakaolin ( NMK ) on some properties (compressive strength ,splitting tensile strength & water absorption ) of concrete. The nano metakaolin (NMK) was prepared by thermal activation of kaolin clay for 2 hours at 750 Ċ. The cement used in this investigation consists of ordinary Portland cement (OPC). The OPC was partially substituted by NMK of ( 3, 5 & 10%) by weight of cement. The C45 concrete was prepared , using water/cement ratio ( W/c) of (0.53) .The Water absorption was tested at 28 days while the tests (compressive strength ,splitting tensile strength) were tested at ages of (7, 28, 60,& 90) days . The compressive strength and splitting tensile strength of concrete with NMK were higher than that of reference concrete with the same W/c ratio.The improvement in the compressive strength when using NMK was (42.2, 55.8 , 63.1% ) at age 28 days for ( 3%, 5%, &10% ) replacement of NMK respectively whereas the improvement in the splitting tensile strength was (0% , 36% & 46.8 %) at age of 28 days when using (3%, 5%, &10% ) NMK respectively. The improvement in the water absorption was (16.6%, 21.79%, &25.6 ) when using (3, 5, &10% )NMK.


Author(s):  
Andrey V. Cherechukin ◽  

The article provides an analysis of key trends in the international market, using the example of the countries of Northeast Asia. In 2019, the world coal market amounted to 1,424.5 million tons, of which 78.1% are energy grades to produce electricity and heat, and 21.9% are in metallurgy, the reserves of which are significantly less. The import coal market of the countries of Northeast Asia in 2019 was already 680 million tons, covering 48% of the entire world coal market. The paper provides an overview of the key importers and exporters of coal in the world, the quantitative and qualitative characteristics of the supplied raw materials, and analyzes the key factors affecting the pricing of coal. In the conclusions, the main trends in the international coal market of the countries of Northeast Asia are presented, including "geographical" — the shift of the center of world trade from Europe to Asia, and "types and quality of imported coal" — an increase in the share of high-quality premium energy and coking (metallurgical). Trends can be clearly seen in the countries of Northeast Asia, which actively use coal, and are making efforts to decarbonize their national economies, while intensifying inter-fuel competition with other primary energy sources.


1984 ◽  
Vol 42 ◽  
Author(s):  
M. Regourd

AbstractHigh strength cement pastes include hot pressed, autoclaved, impregnated low water/cement ratio, macrodefect free, ultrafine particles arrangement systems. The densification of the microstrucure is mainly related to a low porosity and to the formation of poorly crystalline hydrates. In composite systems like mortars and concretes, the interfacial bond between the cement paste and aggregates is moreover less porous and more finely crystallized than the normal “auréole de transition”.


2015 ◽  
Vol 730 ◽  
pp. 11-14 ◽  
Author(s):  
Hai Long Zhang ◽  
Chang Chun Pei

By ANSYS finite element analysis we study the impact-span moment and deflection of high strength recycled concrete beam in state of initial cracking and yield with different water-cement ratio and recycled coarse aggregate replacement rate. The results showed that: 1With the increase of water-cement ratio and recycled coarse aggregate replacement rate, the deflection is on the rise. 2With the increase of recycled coarse aggregate replacement rate, the yield moment has a slight upward trend. And with the increase of water-cement ratio and recycled coarse aggregate replacement rate, the span deflection at the state of yield has a growing trend.


2016 ◽  
Vol 78 (10) ◽  
Author(s):  
Paul O. Awoyera ◽  
Olurotimi M. Olofinnade ◽  
Ayobami A. Busari ◽  
Isaac I. Akinwumi ◽  
Moyosore Oyefesobi ◽  
...  

Several thousands of tons of electric arc furnace slag (EAF) slag generated in Nigeria are yet to be utilised for construction; perhaps as a result of inadequate technical details for its use. The present study has evaluated the effects of varying water-cement ratio on workability and strength of locally generated steel slag aggregate (SSA) concrete. Tested samples include 150 mm concrete cubes and cylinder samples with 150 mm diameter and 300 mm height respectively. SSA was substituted in increments of 20% by weight of granite until 100% mix, while w/c was varied at 0.5, 0.55 and 0.6. Workability of fresh concrete was evaluated through slump test. Hardened concrete cubes and cylinders were subjected to compression and split tensile tests respectively, after 7, 14 and 28 days curing periods. Slump values obtained were in the range of 50 – 90 mm for all the mixes, which represented a S2 slump. Compressive strength and tensile strength increased with age and increasing slag substitution. A strength of 25 MPa for normal weight concrete was achieved at 28 days with 20% SSA substitution, only within 0.5 and 0.55 w/c ratio. However, result obtained for concrete mixes with 60% SSA and above at 28 days established that these mixes are good for production of high strength concrete.


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