The Influence of Cement Content and Water/Cement Ratio on the Durability of Portland Cement Concretes exposed to Silage Effluent

1999 ◽  
Vol 72 (2) ◽  
pp. 137-143 ◽  
Author(s):  
M. Richardson ◽  
V.A. Dodd ◽  
J.J. Lenehan ◽  
S. Conaty ◽  
P. O'Kiely
2011 ◽  
Vol 179-180 ◽  
pp. 978-982
Author(s):  
Xiao Yong Li ◽  
Zhi Gang Zhang

Slurry trench cutoff walls, constructed using self-hardening cement-bentonite (SCB) are the most common form of in-ground vertical contaminant barrier in the world, and are increasingly being used in China. As a kind of vertical anti-seepage wall material, SCB slurry is requently used for the containment of contaminated groundwater and other envirofunental Protection Projeets abroad. Domestie applieation of cement-bentonite slurry walls is not extensive. The objective of this study was to evaluate the effect of water-cement ratio and cement content on the hydraulic behavior of SCB and soil–bentonite (SB) mixtures permeated with water. The experimental program included unconfined compression tests, expansion ratio tests and hydraulic conductivity tests. The test results indicated changes in hydraulic conductivity take place due to the variation of the water-cement ratio and permeant fluid. Cement is a main material in effecting the CSB strength of unconfined compression. Cement greatly influenced the CSB permeability coefficient. Addition of Portland cement to the SB mixtures increased their hydraulic conductivity when permeated with water. The hydraulic conductivity of the SCB specimens permeated with water was inversely related to the cement content.


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.


2016 ◽  
Vol 711 ◽  
pp. 599-606
Author(s):  
Geert de Schutter

Deemed-to-satisfy durability requirements, as typically provided in code prescriptions (minimum cement content, maximum water cement ratio, minimum strength class) are now approaching their limits of applicability. With the implementation of new tailor-made binder types, including a multitude of powders (reactive and even non-reactive), the prescriptive parameters cement content and water/cement ratio become unclear and do not always correlate well with the real durability performance. While the equivalent concrete performance concept (ECPC) already offers a first way out of this debate, it still fundamentally maintains durability requirements at a deemed-to-satisfy level, as the new binder type needs to be experimentally calibrated relative to a standard solution. A more fundamental solution needs to consider the absolute durability performance of the concrete applied in the real structure. This performance needs to be evaluated in laboratory conditions (potential performance) as well as on the final structure (as-built performance). However, although straightforward in principle, the quest for absolute durability performance criteria is complicated, with remaining fundamental obstacles. This paper intends to give a general overview.


2013 ◽  
Vol 438-439 ◽  
pp. 197-201
Author(s):  
Xian Hua Yao ◽  
Peng Li ◽  
Jun Feng Guan

Based on the generalization and analysis of laboratory experimental results on mix ratio, the effects of various factors such as cement content, water-cement ratio, curing time, curing conditions and types of cement on the mechanical properties of unconfined compressive strength of cement soil are presented. Results show that the unconfined compressive strength of cement soil increases with the growing curing time, and it is greatly affected by the cement content, water-cement ratio, cement types and curing time, while the effect of curing conditions is weak with a cement content of more than 10%. Moreover, the stress-strain of the cement soil responds with the cement content and curing time, increasing curing time and cement content makes the cement soil to be harder and brittle, and leads to a larger Young's modulus.


2021 ◽  
Vol 25 (Special) ◽  
pp. 2-78-2-82
Author(s):  
Haider K. Ahmed ◽  
◽  
Mohammed A. Abdulrehman ◽  

Two types of nanomaterial: Tio2 nanoparticles (NPs) and carbon black NPs have used in this research to study their effect on compressive strength, shrinkage and flow table tests Cement mortar. The mixing ratio was 1:2.7:0.485 (cement, sand, water/cement ratio) for compressive strength test and 1:2 (cement, sand) with the water/cement ratio was a variable value for dry shrinkage test. The two nanoparticles’ ratios are (0.25%, 0.75%, 1.25 % and 1.75%) by weight of the Portland cement. The test results show that the highest value of compressive strength was obtained when using Tio2 at 1.25% wt. of cement. But when using carbon black nanoparticles, the greatest value was obtained when adding it with a ratio of 1.75 % wt. of cement. Using two NPs when added to cement mortar has a negative effect on the shrinkage value.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Son Bui Truong ◽  
Nu Nguyen Thi ◽  
Duong Nguyen Thanh

Soft soil is widely distributed in Vietnam, especially in the coastal area. In engineering practice, soft soil cannot be used to build any construction and needs to be improved or treated before building construction. In addition, Vietnam has many pig-iron or thermal power plants, which annually produce a huge amount of granulated blast furnace slag (GBFS). Thus, the use of this material for soft soil improvement needs to be considered. This paper presents experimental results on the unconfined compressive strength (UCS) of three Vietnam’s soft soils treated with Portland cement and Portland cement with ground granulated blast furnace slag (GGBFS). Binder dosage used in this study is 250, 300, and 350 kg/m3 with the three different water/cement ratios of 0.8, 0.9, and 1.0, respectively. The research results showed that the UCS of soil-cement mixtures depends on soil type, water/cement ratio, cement type, and binder content. Accordingly, the unconfined compressive strength increased with the increase of binder contents, the decrease of the natural water content of soft soil, water/cement ratios, and clay content. The highest value of UCS of treated soils was found for the soil at Site II with the Portland cement content, cement GGBFS, and water/cement ratio of 873 kg/m3, 2355 kg/m3, and 0.8, respectively. Besides, for all the three soils and two binder types, the water/cement ratio of 0.8 was found to be suitable to reach the highest UCS values of treated soil. The research results also showed that the UCS of treated soil with cement GGBFS was higher than that of treated soil with Portland cement. This indicated the effectiveness of the use of Portland cement with GGBFS in soft soil improvement. There is great potential for reducing the environmental problems regarding the waste materials from pig-iron plants in Vietnam and the construction cost as well.


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