scholarly journals The Effect of Sisal Juice Extract Admixture on Compressive and Flexural Strength of Cement Concrete

2021 ◽  
Vol 11 (2) ◽  
pp. 7041-7046
Author(s):  
M. O. Eloget ◽  
S. O. Abuodha ◽  
M. M. O. Winja
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Cementitious Materials ◽  
Strength Development ◽  
Concrete Durability ◽  
Flexural Test ◽  
Concrete Compressive Strength ◽  
Cement Concrete ◽  
Shrinkage Cracking ◽  
Lower Permeability

The characteristics of concrete are influenced by the ratio of water to cementitious materials (w/c) used in the mixture. An increase in paste quality will yield higher compressive and flexural strength, lower permeability, increased resistance to weathering, improve the bond between concrete and reinforcement, reduced volume change from drying and wetting, and reduced shrinkage cracking tendencies. Admixtures are used to improve the properties of concrete or mortar. The current study investigates the effect of Sisal Juice Extract (SJE) as an admixture on concrete durability. SJE contains unrefined minerals which can be used as organic retarders to increase the rate of strength development at an early age. A total of 84 concrete cubes were produced in 7 sets of 12 samples each. One set was the control mix which had zero SJE content. The remaining sets had varying dosages of SJ namely 5%, 10%, 15%, 20%, 25%, and 30%. Twelve beam specimens were also cast and subjected to the three-point flexural test. To establish the effect on strength of concrete, compressive strength was tested at 7, 14, 28, and 56 days while flexural strength was tested at 28 days. The highest compressive strength was achieved at 5% dosage beyond which a decrease in strength occurred for all the higher dosages.

scholarly journals Concrete Overstrength: Assessment of Field Strength Seeking Insights for Overdesign Optimization

CivilEng ◽  
2022 ◽  
Vol 3 (1) ◽  
pp. 51-65
Author(s):  
Rodrigo Antunes
Keyword(s):  
Compressive Strength ◽  
Linear Optimization ◽  
Optimization Technique ◽  
Cementitious Materials ◽  
Concrete Durability ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Compressive Strength Of Concrete ◽  
Ready Mixed Concrete

This study investigates the high contents of cementitious materials in Portland cement concrete and assesses the required (f’cr) and actual (σ) compressive strength of concrete specimens. A linear optimization technique identifies the required binder content to reach f’cr. Standard specifications have required concrete overdesign (OD) for decades, but few studies have evaluated the actual magnitude of OD from field data. The compressive strength of 958 cylinders prepared in the field represented 8200 m3 of ready-mixed concrete with 300 and 450 kg/m3 of cementitious are analyzed. The actual OD appears to be 7 to 21% higher than required. The required 28-day compressive strength of concrete was achieved in less than seven days. Therefore, the content of the cementitious materials could be reduced by 6 and 17% so that concrete could reach f’cr without cementitious overconsumption. Reducing cementitious content is recommended to improve construction quality and optimize resource utilization. Among the main reasons for this recommendation are the estimated substantial long-term savings, increased concrete durability and more rational use of natural resources required to build the structures.

scholarly journals Kontribusi Kuat Lentur Polikarbonat Pada Pelat Beton Berpori (The Contribution of Polycarbonate Flexural Strength into Porous Concrete Slab)

2017 ◽  
Vol 1 (01) ◽  
pp. 1
Author(s):  
Dwi Nurtanto
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Flexural Strength ◽  
Thermal Resistance ◽  
Test Specimen ◽  
Concrete Slab ◽  
Thermoplastic Polymer ◽  
Flexural Test ◽  
Concrete Compressive Strength ◽  
Porous Concrete

Polycarbonate is thermoplastic polymer group. It is easily formed using heat. Plastic has many advantages, namely thermal resistance compared to other types of plastic, resistant to impact, and very clear. The purpose of this research is to replace steel in reinforced concrete with polycarbonate and it is expected to contribute a good flexural strength on the porous concrete slab. The test specimen is 40x40x5 cm and the variation widths of polycarbonate are 2 cm, 4 cm, and 6 cm. Polycarbonates are arranged in the x direction and y direction, such as the reinforcement in concrete slab. The distance between the pores in concrete slab is 8 cm. Once the concrete aged 28 days, the next step is testing the flexural strength. The results show the concrete compressive strength is 24.699 MPa. The biggest average flexural test is in porous concrete slab with diameter of reinforcement is 6 mm. Meanwhile, for porous concrete slab without reinforcement and porous concrete slab with polycarbonate have flexural strength which is almost the same. This is because there is no bond between polycarbonate and concrete, so that the adhesion between them is very small and virtually non-existent. In addition, the results show that there is no contribution of polycarbonate flexural strength in concrete slab. Polikarbonat adalah suatu kelompok polimer termoplastik yang mudah dibentuk dengan menggunakan panas. Plastik ini memiliki banyak keunggulan, yaitu ketahanan termal dibandingkan dengan plastik jenis lain, tahan terhadap benturan, dan sangat bening. Tujuan penelitian ini adalah mengganti material baja pada beton bertulang dengan polikarbonat dan diharapkan dapat memberikan kontribusi kuat lentur yang baik pada pelat beton berpori. Ukuran benda uji adalah 40x40x5 cm, dimana variasi ukuran lebar polikarbonat adalah 2 cm, 4 cm dan 6 cm. Polikarbonat disusun dalam arah x dan arah y, seperti penulangan pada pelat beton. Selanjutnya dilakukan pengecoran. Jarak antar pori pada pelat beton adalah 8 cm. Setelah beton berumur 28 hari maka dilakukan pengujian kuat lentur. Hasil penelitian menunjukkan kuat tekan karakteristik beton adalah sebesar 24.699 MPa. Hasil kuat lentur rata-rata yang paling besar terjadi pada pelat beton berpori dengan tulangan diameter 6 mm, sedangkan untuk plat beton berpori tanpa tulangan dan dengan polikarbonat hasil kuat lenturnya hampir sama. Hal ini dikarenakan tidak adanya lekatan antara lembaran polikarbonat dan beton, sehingga daya lekat polikarbonat terhadap beton sangat kecil dan bisa dikatakan tidak ada. Selain itu, hasil menunjukkan bahwa tidak adanya kontribusi kuat lentur polikarbonat pada beton berpori.

scholarly journals Long-term mechanical and shrinkage properties of cementitious grouts for structural repair

2019 ◽  
Vol 4 ◽  
pp. 9-15
Author(s):  
Md Shamsuddoha ◽  
Götz Hüsken ◽  
Wolfram Schmidt ◽  
Hans-Carsten Kühne ◽  
Matthias Baeßler
Keyword(s):  
Fly Ash ◽  
Flexural Strength ◽  
Cementitious Materials ◽  
Response Surfaces ◽  
Supplementary Cementitious Materials ◽  
Strength Development ◽  
Structural Repair ◽  
Positive Effects ◽  
Micro Silica

Grouts have numerous applications in construction industry such as joint sealing, structural repair, and connections in precast elements. They are particularly favoured in rehabilitation of structures due to penetrability and convenience of application. Grouts for repair applications typically require high-performance properties such as rapid strength development and superior shrinkage characteristics. Sometimes industrial by-products referred as supplementary cementitious materials (SCM) are used with neat cement due to their capabilities to provide binding properties at delayed stage. Micro silica, fly ash and metakaolin are such SCMs, those can modify and improve properties of cement products. This study aims at investigating long-term mass loss and linear shrinkage along with long-term compressive and flexural strength for grouts produced from ultrafine cement and SCMs. A series of mixtures were formulated to observe the effect of SCMs on these grout properties. Properties were determined after 365 days of curing at 23oC and 55% relative humidity. The effect of SCMs on the properties are characterised by statistical models. Response surfaces were constructed to quantify these properties in relation to SCMs replacement. The results suggested that shrinkage was reduced by metakaolin, while micro silica and fly ash had positive effects on compressive and flexural strength, respectively.

scholarly journals Effect of Soorh Metakaolin on Concrete Compressive Strength and Durability

2017 ◽  
Vol 7 (6) ◽  
pp. 2210-2214 ◽  
Author(s):  
A. Saand ◽  
M. A. Keerio ◽  
D. K. Bangwar
Keyword(s):  
Compressive Strength ◽  
Corrosion Resistance ◽  
Life Time ◽  
Natural Material ◽  
Concrete Durability ◽  
Concrete Compressive Strength ◽  
Water Penetration ◽  
Carbonation Depth ◽  
Ordinary Concrete ◽  
Strength And Durability

Concrete durability is a key aspect for forecasting the expected life time of concrete structures. In this paper, the effect of compressive strength and durability of concrete containing metakaolin developed from a local natural material (Soorh of Thatta Distict of Sindh, Pakistan) is investigated. Soorh is calcined by an electric furnace at 8000C for 2 hours to produce metakaolin. One mix of ordinary concrete and five mixes of metakaolin concrete were prepared, where cement is replaced by developed metakaolin from 5% to 25% by weight, with 5% increment step. The concrete durability was tested for water penetration, carbonation depth and corrosion resistance. The obtained outcomes demonstrated that, 15% replacement level of local developed metakaolin presents considerable improvements in concrete properties. Moreover, a considerable linear relationship was established between compressive strength and concrete durability indicators like water penetration, carbonation depth and corrosion resistance.

scholarly journals Influence of Glass Fibers on Mechanical Properties of Concrete with Recycled Coarse Aggregates

2019 ◽  
Vol 5 (5) ◽  
pp. 1007-1019 ◽  
Author(s):  
Babar Ali ◽  
Liaqat Ali Qureshi ◽  
Ali Raza ◽  
Muhammad Asad Nawaz ◽  
Safi Ur Rehman ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Mechanical Performance ◽  
Volume Fraction ◽  
Glass Fibers ◽  
Construction Material ◽  
Concrete Compressive Strength ◽  
Coarse Aggregates ◽  
Highly Sensitive

Despite plain cement concrete presenting inferior performance in tension and adverse environmental impacts, it is the most widely used construction material in the world. Consumption of fibers and recycled coarse aggregates (RCA) can add ductility and sustainability to concrete. In this research, two mix series (100%NCA, and 100%RCA) were prepared using four different dosages of GF (0%GF, 0.25%GF, 0.5%GF, and 0.75%GF by volume fraction).  Mechanical properties namely compressive strength, splitting tensile strength, and flexural strength of each concrete mixture was evaluated at the age of 28 days. The results of testing indicated that the addition of GF was very useful in enhancing the split tensile and flexural strength of both RCA and NCA concrete. Compressive strength was not highly sensitive to the addition of GF. The loss in strength that occurred due to the incorporation of RCA was reduced to a large extent upon the inclusion of GF. GF caused significant improvements in the split tensile and flexural strength of RCA concrete. Optimum dosage of GF was determined to be 0.25% for NCA, and 0.5% for RCA concrete respectively, based on the results of combined mechanical performance (MP).

Effect of Ground Granulated Blast Furnace Slag on Compressive Strength of POFA Blended Concrete

2015 ◽  
Vol 802 ◽  
pp. 142-148
Author(s):  
M.N. Noor Azline ◽  
Farah Nora Aznieta Abd Aziz ◽  
Arafa Suleiman Juma
Keyword(s):  
Compressive Strength ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Strength Development ◽  
Replacement Level ◽  
Concrete Compressive Strength ◽  
Cement Replacement ◽  
Granulated Blast Furnace Slag ◽  
Strength Tests ◽  
Furnace Slag

The article reports a laboratory experimental programme that investigated effect of ground granulated blast furnace (GGBS) on compressive strength of POFA ternary concrete. Compressive strength tests were performed at a range of cements combinations, including 100%PC, two POFA levels for binary concrete, 35% and 45%, and 15%GGBS inclusion for POFA ternary concrete. The compressive strength results were examined in comparison to PC only and equivalent POFA binary concretes for up to 28 days. Results show that the reduction in compressive strength is greater with the higher cement replacement level for all concretes particularly for POFA binary concretes. However, 15%GGBS in POFA blended concrete has a comparable compressive strength compared to PC concrete at both, 35% and 45%, cement replacement levels except for ternary concrete at 0.65 w/c. In addition, the compressive strength of ternary concrete is slightly higher compared to binary concrete for all concrete combinations. Although there is no significant noticeable influence on strength development, the presence of GGBS did not adverse the strength development of POFA blended concrete. Thus, it can be concluded that GGBS compensates the adverse effect of POFA at early strength development.

scholarly journals Effect of Aggregate Type and Specimen Configuration on Concrete Compressive Strength

Crystals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 625 ◽  
Author(s):  
Sherif Yehia ◽  
Akmal Abdelfatah ◽  
Doaa Mansour
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Modulus Of Elasticity ◽  
American Concrete Institute ◽  
Recycled Aggregates ◽  
Concrete Compressive Strength ◽  
Split Tensile Strength ◽  
Standard Size ◽  
Noticeable Effect ◽  
The Difference

In this paper, concrete mixes utilizing two sizes of natural aggregate and two sources of lightweight and recycled aggregates were used to investigate the effect of aggregate type and specimen size and shape on the compressive strength of concrete. In addition, samples from ready-mix concrete producers with different strengths were evaluated using standard size cylinders and cubes. Results were obtained on the 7th, 28th, and 90th day. In addition, flexural strength, split tension, and modulus of elasticity were evaluated on the 28th and 90th day. Statistical analyses were conducted to examine the significance of the difference between the compressive strength values for each two mixes using tests of hypotheses. Moreover, other mechanical properties as a function of compressive strength were discussed and compared to those predicated by the American Concrete Institute (ACI) specifications. Results indicate specimen shape has a noticeable effect on the compressive strength as the Cylinder/Cube ratio on the 90th day was ranging between 0.781 and 0.929. The concrete compressive strength and modulus of elasticity were significantly affected by the aggregate type. The flexural strength and split tensile strength were less affected by the aggregate type, which was also confirmed by the values predicted with the ACI equations.

Improving the Durability of High Early Strength (HES) Concrete Patching Materials for Concrete Pavements

2020 ◽  
Vol 2674 (8) ◽  
pp. 12-23
Author(s):  
Cameron Wilson ◽  
W. Jason Weiss
Keyword(s):  
Cement Content ◽  
Autogenous Shrinkage ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Strength Development ◽  
Concrete Pavements ◽  
Shrinkage Cracking ◽  
Concrete Mixtures ◽  
Water To Cement Ratio ◽  
Early Strength

High early strength (HES) concrete patching materials are increasingly used to repair damaged pavements. The use of HES concrete enables the repaired pavement to be opened to traffic shortly after the repair has been installed; for example, opening pavements to traffic 4–6 h after the concrete is placed is becoming more common. HES concrete mixtures are typically designed with a low water-to-cement ratio and a high cement content; they contain accelerating admixtures and limited supplementary cementitious materials. As a result, these HES patches may be susceptible to self-desiccation, causing autogenous shrinkage and early age cracking. Self-desiccation can lead to reduced hydration, limited strength gain, and overestimation of strength development in maturity-based predictions. The objectives of this study are threefold. First, the paper will illustrate how self-desiccation can lead to the premature cessation of hydration and increased potential for shrinkage cracking. Second, the paper will illustrate how maturity-based predictions can be modified to account for self-desiccation. Third, internal curing is discussed as a way to mitigate self-desiccation and shrinkage ultimately improving the performance of HES concrete patching materials.

Sign in / Sign up

Export Citation Format

Share Document