Influence of Cement and Sand Type on the Strength Characteristics of Mortars with Various Contents of Green Binder

Covatariu

et al. 2013

AMR

Self Cite

The paper presents some preliminary results on using a new supplementary Cementitious material based on industrial by-products most of them unrecyclable until recently. The opportunity for using such industrial unrecyclable wastes in construction industry has recently been recognized by researchers as having net benefits for the environment. This strategy has the potential to reduce costs, conserve energy and minimize waste. The concept very much fits into the era of sustainable development. In view of this fact, the effect of curing conditions on the self weight and strength characteristics of an eco-mortar is studied and preliminary encouraging results are presented. The eco-cement, in the form of anhydrous calcium sulphate, is set to replace the ordinary Portland cement in the mix proportion. It is made from industrial wastes and can be entirely recycled after its expiration date. The curing conditions consisted in air curing for 28 days or various time intervals for curing in water until the day of testing. The strength properties at the age of 28 days are investigated in terms of bending tensile strength and compressive strength. The obtained results show that the curing conditions play an important role both on the self weight and on the strength characteristics.

Section: Materials and Methodologymentioning

confidence: 99%

Greening of Concrete Industry by Incorporating Gypsum-Based Industrial Wastes as Supplementary Cementitious Materials

Covatariu

et al. 2013

AMR

Self Cite

“…The novel Cementitious material used in the present research is obtained from industrial wastes, most of them unrecyclable until recently [23]. Its properties, in conjunction with ordinary Portland cement, have been extensively studied in terms of strength and elastic characteristics [13]. Additionally, the effect of curing conditions was also examined [24] and it was concluded that in terms of the self weight a water curing period of 7 days or 14 days led to better values.…”

Section: Methodsmentioning

confidence: 99%

“…The range of lateral displacement was 0 ÷ ±30 mm. The strength characteristics of the jacketing material were experimentally determined for various percentages of Portland cement replacement by the novel Cementitious material [13]. Additionally, the elastic properties were also determined according to ASTM C469 [27] specifications.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Evaluation of the Load Carrying Capacity of Short RC Columns Strengthened with a Novel Cementitious Material by Using FEA

Covatariu

Lungu

et al. 2013

AEF

Self Cite

Numerical simulations based on the Finite Element Method (FEM) have become an important tool in studying various phenomena of interest to both researchers and practitioners alike. The recent advances in computational power coupled with accurate mathematical models have made FEM an indispensable tool for investigating complex loading states and material behavior that are frequently met in civil engineering. Strengthening of existing RC columns is becoming a pressing issue in the field of civil engineering due to the necessity of meeting new safety requirements for the buildings located in active seismic areas. Jacketing is a widely used method for strengthening of reinforced concrete columns showing good results in terms of increased strength and stiffness but with the addition of some unwanted effects amongst which the added dead weight is of primary importance in case of an earthquake. The paper presents the results obtained by means of Finite Element Analysis (FEA) on the load carrying capacity of short RC columns strengthened with a novel Cementitious material that may be the solution to lighter structures and lower added costs compared to other existing methods.

“…The obtained results showed a decrease in the flexural and compressive strengths of mortars with small replacing percentages of anhydrous calcium sulphate. However, the flexural strength increased tremendously for higher percentages of anhydrous calcium sulphate [8][9].A study was conducted in which weathered (stored in open-air) phosphogypsum was utilized as a set retarder in Portland cement. The effects on the setting and mechanical properties of PG added in ratios 1,3,5,7,10,and 12.5wt.% to Portland cements was investigated and compared with a Portland cement containing natural gypsum (NG).…”

Section: Introductionmentioning

confidence: 99%

Behavior of Cement Pastes and Mortar Containing Phosphogypsum

Nouhy¹,

Khattab²,

Zeedan

2015

KEM

The aim of this study is to investigate the effects of phosphogypsum on the properties of both cement pastes and mortars. Normal Portland cement CEM Ι 32,5N, Limestone Blended cement CEM ΙΙ B-L32,5N, and Slag cement CEM ΙΙ A-S32,5N were used. These cements were partially substituted by 0,2,4,6,8,10,and 15% of phosphogypsum. The test program was divided to two stages. In the first stage, tests were conducted according to BSEN 196, namely setting times (initial and final), soundness, and compressive strength (at ages 7 and 28 days). In the second stage, X-ray diffraction (XRD), and scanning electron microscope (SEM) were conducted on selected mixes from first stage. The results show that the three types of cements with the various replacement percentages of phosphogypsum met the limit of initial setting time, as well as, provided soundness of 2 mm. Also, in terms of compressive strength, it was proven, that it is possible to partially replace the three tested types of cements by phosphogypsum by up to 8%and 15% with regard to cement/sand ratio of (1:3) and (1:2) respectively.