Garuda - Garba Rujukan Digital

p-Index From 2019 - 2024

1.784

P-Index

This Author published in this journals

All Journal JURNAL DIMENSI UTAMA TEKNIK SIPIL Jurnal Dimensi Pratama Teknik Sipil Civil Engineering Dimension Dimensi Utama Teknik Sipil

Djwantoro Hardjito

Petra Christian University

Author-ID : 275519

Civil Engineering, Building, Construction & Architecture

Published : 80 Documents Claim Missing Document

Claim Missing Document

Articles

Title

FACTORS INFLUENCING THE COMPRESSIVE STRENGTH OF FLY ASH-BASED GEOPOLYMER CONCRETE Djwantoro Hardjito; Steenie E Wallah; Dody M.J. Sumajouw; B.V Rangan
Civil Engineering Dimension Vol. 6 No. 2 (2004): SEPTEMBER 2004
Publisher : Institute of Research and Community Outreach - Petra Christian University

This paper describes the effects of several factors on the properties of fly ash based geopolymer concrete, especially the compressive strength. The test variables included were the age of concrete, curing time, curing temperature, quantity of superplasticizer, the rest period prior to curing, and the water content of the mix. The test results show that the compressive strength of geopolymer concrete does not vary with age, and curing the concrete specimens at higher temperature and longer curing period will result in higher compressive strength. Furthermore, the commercially available Naphthalene-based superplasticizer improves the workability of fresh geopolymer concrete. The start of curing of geopolymer concrete at elevated temperatures can be delayed at least up to 60 minutes without significant effect on the compressive strength. The test data also show that the water content in the concrete mix plays an important role.

Simple Mechanical Beneficiation Method of Coarse Fly Ash with High LOI for Making HVFA Mortar Antoni ,; Vindy Satrya; Djwantoro Hardjito
Civil Engineering Dimension Vol. 17 No. 1 (2015): MARCH 2015
Publisher : Institute of Research and Community Outreach - Petra Christian University

This study focusses on the effect of milling of fly ash obtained from four different sources on the properties of high volume fly ash (HVFA) mortar. Two fly ash samples with low loss-on-ignition (LOI) were taken from a coal-fired power plant, while the other two with high LOIs were obtained from a textile factory and from a paper mill, respectively. Milling was performed using a rod mill at a certain period of time. The workability of HVFA mortar with constant water to cementitious ratio was controlled by adjusting the superplasticizer content. The results show that the specific gravity of fly ash increases after milling. Utilizing milled fly ash ends up with significant strength increase of HVFA mortar, especially those utilizing high LOI fly ash. This shows that milling is an excellent fly ash beneficiation technique, especially on the one with high LOI value.

Influence of Particle Size Distribution of High Calcium Fly Ash on HVFA Mortar Properties Antoni .; Hendra Surya Wibawa; Djwantoro Hardjito
Civil Engineering Dimension Vol. 20 No. 2 (2018): SEPTEMBER 2018
Publisher : Institute of Research and Community Outreach - Petra Christian University

This study evaluates the effect of particle size distribution (PSD) of high calcium fly ash on high volume fly ash (HVFA) mortar characteristics. Four PSD variations of high calcium fly ash used were: unclassified fly ash and fly ash passing sieve No. 200, No. 325 and No. 400, respectively. The fly ash replacement ratio of the cementitious material ranged between 50-70%. The results show that with smaller fly ash particles size and higher levels of fly ash replacement, the workability of the mixture was increased with longer setting time. There was an increase in mortar compressive strength with finer fly ash particle size, compared to those with unclassified ones, with the highest strength was found at those with fly ash passing mesh No. 325. The increase was found due to better compactability of the mixture. Higher fly ash replacement reduced the mortar’s compressive strength, however, the rate was reduced when finer fly ash particles was used.

Utilization of low sulfur fly ash from circulating fluidized bed combustion burner as geopolymer binder Antoni Antoni; Stacia Dwi Shenjaya; Maria Lupita; Samuel Santosa; David Wiyono; Djwantoro Hardjito
Civil Engineering Dimension Vol. 22 No. 2 (2020): SEPTEMBER 2020
Publisher : Institute of Research and Community Outreach - Petra Christian University

Circulating fluidized bed combustion (CFBC) is a newer type of burner that employ a circulating process to burn fuel effectively. CFBC burning process is gaining more popularity due to its compact size, high efficiency and lower burning temperature compared to the pulverized coal combustion (PCC) burner. The CFBC burner produces fly ash with different physical properties compared to the PCC burner, i.e. the fly ash is not rounded, and required higher water content for comparable workability. The CFBC fly ash also has a high sulfur content that is detrimental for hardened concrete. Due to its drawbacks, the CFBC hardly used as cementitious material and geopolymer precursor. This study focuses on comparing variations in the concentration of NaOH solution and variations in the ratio of alkaline activators to the setting time and compressive strength of geopolymer mortars on a new class of CFBC fly ash, which have low sulfur content. The concentrations of NaOH solution were 6M, 8M, 10M, and 12M, while the alkaline activator ratios used were 3.0, 2.5, 2.0, 1.0, and 0.5. It was concluded that the low sulfur CFBC fly ash has a potential to be utilized as geopolymer precursor, however, with a shortcoming in its high water demand. The CFBC fly ash used in this study resulted in a geopolymer matrix with good compressive strength and stability. The water demand varies with the fly ash sampling time shows the challenges in the utilization of the fly ash. The highest mortar’s compressive strength, 33.4 MPa at 90 days was achieved at NaOH concentration of 8M and ratio of sodium silicate solution to sodium hydroxide solution of 2.5 with excellent stability.

Long-term Mechanical Properties and Microstructure of Concrete Utilizing Self-Cementing Fly Ash as A Sole Binder Material Oswyn Karsten Wattimena; Antoni Antoni; Djwantoro Hardjito
Civil Engineering Dimension Vol. 25 No. 2 (2023): SEPTEMBER 2023
Publisher : Institute of Research and Community Outreach - Petra Christian University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9744/ced.25.2.106-114

Self-cementing fly ash, containing calcium oxide (CaO) of about 20%, has successfully become a sole binder material in concrete through hydration. A very low water-to-fly ash ratio, e.g., below 0.20, is the main key to achieving the high compressive strength of concrete. This study explores the strength evolution, long-term compressive strength, and mechanical properties of concrete that utilize self-cementing fly ash as a sole binder material. Remarkably, the long-term compressive strength continues to develop over a year, reaching nearly 50 MPa at 365 days, a 34% increase from the 28-day strength. While the other mechanical properties are slightly lower than predictions from empirical formulas for Portland cement concrete, promising results are observed. Scanning Electron Microscope (SEM) images highlight surface-restricted hydration products in self-cementing fly ash, rather than full dissolution of fly ash particles.

Co-Authors , Antoni Agie Vianthi Agie Vianthi Agung Sugiarto Albert Natanegara Albertus Yonathan Aldi Vincent Sulistio Aldwin Ivan Gan Aldwin Ivan Gan Aleksander Jodjana Aleksander Jodjana Alvin Adiputra Widjaja Alvin Adiputra Widjaja, Alvin Adiputra Alvin Cahyadi Djoewardi Alvin Cahyadi Djoewardi Alvin Krisnanta Widianto Alvin Krisnanta Widianto, Alvin Krisnanta Andi Widjaya Andi Widjaya Andreas Andreas Andry Wirananda Angdiarto, Stella Patricia Anton Prayogo Go Anton Prayogo Go Antoni , Antoni , Antoni . Antoni . Antoni . Antoni Antoni Antoni Antoni Antoni Antoni Antoni Antoni Antoni Antoni Antoni Antoni Ariyanto Mulya Sim Ariyanto Mulya Sim, Ariyanto Mulya Arnold Phengkarsa Arnold Phengkarsa Arthur Arthur Austin Purwantoro B.V Rangan Benedictus Trista Dmitri Billy Susilo Billy Susilo, Billy Chrisco Nathaniel Thomas Christanto, Daniel Chrysilla Natallia Chrysilla Natallia Chrystian Hadinata Crystie Angelina Leuw Crystie Angelina Leuw Daniel Christanto David Christianto David Christianto David Wiyono David Wiyono David Wiyono David Wiyono Dewanti Ratna Paramitha Diar Januar Utomo Diar Januar Utomo Dmitri, Benedictus Trista Dody M.J. Sumajouw Ediantonius Lubis Edvan Benefisco Edwin Christian Edwin Valentino Edwin Valentino Eric Budisetiawan Eric Budisetiawan Erwin Suryawangi Erwin Suryawangi Evelin Anastasia Fanuel Jeffry Christianto Fanuel Jeffry Christianto Febrina Ekaputri Susanto Febrina Ekaputri Susanto, Febrina Ekaputri Felicia Tria Nuciferani Gan, Aldwin Ivan Gary Kartadinata Gary Kartadinata Geraldo Theodore Santoso Gerardus Abi Gerardus Abi, Gerardus Ghozali, Kurniawati Ester Goey Frengki Gregorius Franky Tanggu Hans Tobias Wijaya Hendra S. Wibawa Hendra S. Wibawa Hendra Surya Wibawa Henry Sutikno Hilda Utami Citra Hilda Utami Citra Jason Ghorman Herianto Jerry Laksmana Wiranegara Jerry Laksmana Wiranegara, Jerry Laksmana Jonathan Robby Joshua Wilson Thiofilus Juan Satria Juan Satria, Juan Kent Setiono Kevin Desailly Kevin Guyana Kevin Klarens Kevin Saputra Kevin Saputra Yusuf Krisno Phoanajaya Krisno Phoanajaya Kristella Nathania Lairenz Kurniawati Ester Ghozali Lucky Chandra Lucky Chandra Lydia Yuniarti Meok Maria Lupita Maria Lupita Masyogo Pangestu Masyogo Pangestu, Masyogo Michael Benjamin Honny Michael Indranata Natanegara, Albert Nataniel Alexsander Roberto Nico Christiono Oswyn Karsten Wattimena Owen Malvin Sirapanji Permana Putra Prasetio Permana Putra Prasetio Raven Andrean Subroto Raven Andrean Subroto Reiner Tirtamulya Surja Ricard Mintura Ricky Surya Ryan Renaldo Wijaya Sam Wahyudi Winata Sam Wahyudi Winata Samuel Santosa Samuel Wahjudi Singgih Suryajaya Stacia Dwi Shenjaya Stacia Dwi Shenjaya Stanley Filberto Steenie E. Wallah Stella Patricia Angdiarto Sugiarto, Agung Sutikno, Henry Teguh Hermawan Widodo Teguh Hermawan Widodo Thomas, Chrisco Nathaniel Vellyana Wardoyo Vindy Satrya Wangsa Hioewono Chandra Wardoyo, Vellyana Wempy Erlando Widya Suyanto William Alexander Yoanes Maria Louis Adhi Prasetya Yohanes Christian Yohanes Takarendehang Yohanes Takarendehang Yonathan, Albertus

Title Search

Found 5 Documents Search Journal : Civil Engineering Dimension

Abstract

Abstract

Abstract

Abstract

Abstract

Title

Found 5 Documents
Search
Journal : Civil Engineering Dimension