scholarly journals Improved Powder Equivalence Model for the Mix Design of Self-Compacting Concrete with Fly Ash and Limestone Powder

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Jingbin Zhang ◽  
Miao Lv ◽  
Xuehui An ◽  
Dejian Shen ◽  
Xinyi He ◽  
...  
Keyword(s):  
Fly Ash ◽  
Carbon Dioxide Emissions ◽  
Unit Volume ◽  
Design Method ◽  
Mix Design ◽  
Limestone Powder ◽  
Self Compacting Concrete ◽  
Threshold Theory ◽  
Equivalence Model ◽  
Plane Area

The use of fly ash (FA) limestone and powder (LP) in combination with cement in concrete has several practical, ecological, and economic advantages by reducing carbon dioxide emissions, reducing the excessive consumption of natural resources, and contributing to a cleaner production of self-compacting concrete (SCC). A mix design method for SCC based on paste rheological threshold theory can guide the SCC mix design by paste tests. This method can be visualized by the self-compacting paste zone (SCP zone), a plane area where all the mix points meet the paste threshold theory, and SCC zone, a plane area consisting of all the mix points satisfying the criteria of qualified SCC. In the case of cement SCC, the SCP zone coheres with the SCC zone. However, in the case of the addition of FA or LP with different granulometry and shape characteristics from cement, experimental results indicate that the SCP zone is separated from the SCC zone. This work quantitatively studied the influence of FA and LP on the movement of the SCP zone by introducing the improved powder equivalence model. The improved model was obtained by powder equivalence coefficients calculated through the mortar test results with or without FA or LP, instead of SCC tests in the former method. The equivalence coefficients by volume of FA and LP are 0.55 and 0.79, respectively, which means that 1.82 unit volume of FA or 1.27 unit volume of LP is equivalent to one unit volume of cement. The improved powder equivalence model was verified by the successful preparation of SCC incorporating FA or LP simply and effectively. The equivalent SCP zone cohered better with the SCC zone than the former SCP zone, which could guide the quick mix design of SCC without SCC premix tests.

scholarly journals Mix proportioning of M80 grade Self-Compacting Concrete based on Nan Su Mix design method principles

2018 ◽  
Vol 7 (3.35) ◽  
pp. 52
Author(s):  
S Shrihari ◽  
M V Seshagiri Rao ◽  
V Srinivasa Reddy ◽  
Venkat Sai
Keyword(s):  
Fly Ash ◽  
High Performance ◽  
Design Method ◽  
High Strength ◽  
Mix Design ◽  
Fine Aggregate ◽  
Self Compacting Concrete ◽  
Mix Proportioning ◽  
Major Factors ◽  
Powder Content

The quest for the development of high strength and high performance concretes has increased considerably in recent times because of the demands from the construction industry. High-performance concretes can be produced at lower water/powder ratios by incorporating these supplementary materials. Fly ash addition proves most economical among these choices, even though addition of fly ash may lead to slower concrete hardening. However, when high strength is desired, use of silica fume is more useful. This paper proposes a mix proportions for M80 grade Self-compacting concrete (SCC) based on Nan Su mix design principles. First, the amount of aggregates required is determined, and the paste of binders is then filled into the voids of aggregates to ensure that the concrete thus obtained has flowability, self-compacting ability and other desired SCC properties. The amount of aggregates, binders and mixing water, as well as type and dosage of superplasticizer (SP) to be used are the major factors influencing the properties of SCC. Slump flow, V-funnel, L-flow, U-box and compressive strength tests were carried out to examine the performance of SCC, and the results indicate that the Nan Su method could produce successfully SCC of high strength. Based on Nan Su mix design method, material quantities such as powder content ( Cement + Pozzolan ), fine aggregate, coarse aggregate, water and dosages of SP and VMA,  required for 1 cu.m,  are evaluated for High strength grade (M80) of Self Compacting Concrete (SCC) are estimated. Final quantities, of M80 grade SCC mix, is assumed after several trial mixes on material quantities computed using Nan Su mix design method subjected to satisfaction of EFNARC flow properties. 

A mix design method of fly ash geopolymer concrete based on factors analysis

2020 ◽  
pp. 121612
Author(s):  
Chenchen Luan ◽  
Xiaoshuang Shi ◽  
Kuanyu Zhang ◽  
Nodir Utashev ◽  
Fuhua Yang ◽  
...  
Keyword(s):  
Fly Ash ◽  
Design Method ◽  
Mix Design ◽  
Geopolymer Concrete ◽  
Factors Analysis

scholarly journals Studi Pemanfaatan Prekursor Fly Ash Lokal pada Self Compacting Geopolymer Concrete (SCGC)

2021 ◽  
Vol 24 (2) ◽  
pp. 111-119
Author(s):  
Evelyn Anabela Anisa ◽  
Rahmad Afriansya ◽  
Julian Randisyah ◽  
Pinta Astuti
Keyword(s):  
Fly Ash ◽  
Mix Design ◽  
Geopolymer Concrete ◽  
Self Compacting Concrete ◽  
Slump Flow

Beton merupakan suatu material yang banyak digunakan dalam dunia konstruksi. Namun, setiap produksi beton menimbulkan dampak buruk pada pemanasan global. Semen sebagai bahan pengikat beton dapat menyumbang emisi CO2 sebanyak 8% dalam setiap produksinya. Proses pengecoran pada beton juga dapat menghasilkan polusi suara akibat penggunaan alat vibrator. Para peneliti terus berupaya menghasilkan beton yang lebih ramah lingkungan. Self Compacting Geopolymer Concrete (SCGC) merupakan kombinasi baru antara beton geopolimer dan Self Compacting Concrete (SCC) yang masih terus diteliti dan dikembangkan hingga saat ini. SCGC merupakan beton ramah lingkungan karena tidak menggunakan semen portland sebagai bahan pengikatnya. Penggunaan beton SCGC tidak memerlukan vibrator karena memiliki sifat flowability yang baik. Penelitian ini menggunakan bahan pengikat berupa material pozzolan yang mengandung senyawa kimia berupa SiO2 dan Al2O3. Tahapan penelitian ini dilakukan dengan mencari metode curing dan mix design optimal dalam penyusunan SCGC. Pengujian XRF perlu dilakukan dalam penelitian ini untuk mengetahui kandungan senyawa kimia pada fly ash Tjiwi Kimia. Beberapa pengujian beton segar SCGC diperoleh hasil berupa slump flow 690 mm, T50 2,4 detik, v-funnel 8,35 mm, dan rasio l-box 0,84. Sifat mekanik beton diuji berdasarkan kuat tekan, kuat tarik belah, dan kuat lentur dengan hasil rata-rata sebesar 27,05 MPa, 6,32 MPa, 1,91 MPa.

scholarly journals Estimating Slump Flow and Compressive Strength of Self-Compacting Concrete Using Emotional Neural Networks

2020 ◽  
Vol 10 (23) ◽  
pp. 8543
Author(s):  
Mosbeh R. Kaloop ◽  
Pijush Samui ◽  
Mohamed Shafeek ◽  
Jong Wan Hu
Keyword(s):  
Neural Network ◽  
Compressive Strength ◽  
Fly Ash ◽  
Pearson Correlation ◽  
Limestone Powder ◽  
Group Method ◽  
Self Compacting Concrete ◽  
Slump Flow ◽  
Powder Content ◽  
The Impact

The characteristics of fresh and hardened self-compacting concrete (SCC) are an essential requirement for construction projects. Moreover, the sensitivity of admixture contents of SCC in these properties is highly impacted by that cost. The current study investigates to estimate the slump-flow (S) and compressive strength (CS), as fresh and hardened properties of SCC, respectively. Four developed soft-computing approaches were proposed and compared, including the group method of data handling (GMDH), Minimax Probability Machine Regression (MPMR), emotional neural network (ENN), and hybrid artificial neural network-particle swarm optimization (ANN-PSO), to estimate the S and 28-day CS of SCC, which comprises fly ash (FA), silica fume (SF), and limestone powder (LP) as part of cement by mass in total powder content. In addition, the impact of eight admixture components is investigated and evaluated to assess the sensitivity of admixture contents for the modelling of S and CS of SCC. The results demonstrate that the performance prediction of ENN model is more significant than other models in estimating S and CS characteristics of SCC. The overall of Pearson correlation coefficient, r, and root mean square error (RMSE) of ENN model are 97.80% and 20.16 mm, respectively, for the S. These are 96.07% and 2.59 MPa, respectively, for the CS. Furthermore, the sensitivity of the powder content of fly ash is shown to have a high impact on the estimated S and CS values of SCC.

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