Improving the quality of recycled fine aggregates by selective removal of brittleness defects

2018 ◽  
Vol 18 (1) ◽  
pp. 49-58
Author(s):  
Roza Mildawati

[ID] Concrete is a very popular building material used in the world of construction services, consisting of a mixture of Portland Cement (PC) or other hydraulic cement, fine aggregates, coarse aggregates and water, with or without using additional materials. The quality of materials such as cement also greatly affects the strength of the concrete after hardening, so the selection of cement quality must be in accordance with the concrete planning regulations in order to obtain optimal results. In Indonesia there are many new cement factories that produce to meet the needs of the community, one of which is the Conch brand cement. So in connection with the above, Conch cement can be examined to compare the value of compressive strength and flexural strength with old cement, namely cement Padang, Tiga Roda, Holcim and Bosowa which are generally always used in concrete planning at this time.The purpose of this study was to determine the comparison of compressive strength and flexural strength of the concrete and the multiplier between cement Padang, Three Wheels and Conch at 28 days of age. In this study using the method SNI 03-2834-2000. With cylindrical test specimens (150 mm x 300 mm) and size beams (150 mm x 150 mm x 600 mm) three specimens were made for each cement.The maximum concrete compressive strength is found in Padang cement with a compressive strength of 45.86 Mpa, for the minimum compressive strength found in Tiga Roda cement with compressive strength value of 40.19 Mpa and for the compressive strength of cement Conch there is a second with compressive strength value 42.84 Mpa. From the explanation above, the results of 28 days of concrete compressive strength with each cement brand still not reached the planned concrete compressive strength of 38 MPa. The maximum concrete flexural strength is found in Padang cement with a flexural strength value of 5.03 Mpa, for a minimum flexural strength value found in Tiga Roda cement with a flexural strength value of 3.96 Mpa and for the value of Conch cement compressive strength there is a second with flexural strength 4.43 Mpa. From the explanation above, the results of 28 days of concrete flexural strength with each cement brand that has not reached the 4.4 Mpa plan, namely the three-wheeled cement brand. [EN] Concrete is a very popular building material used in the world of construction services, consisting of a mixture of Portland Cement (PC) or other hydraulic cement, fine aggregates, coarse aggregates and water, with or without using additional materials. The quality of materials such as cement also greatly affects the strength of the concrete after hardening, so the selection of cement quality must be in accordance with the concrete planning regulations in order to obtain optimal results. In Indonesia there are many new cement factories that produce to meet the needs of the community, one of which is the Conch brand cement. So in connection with the above, Conch cement can be examined to compare the value of compressive strength and flexural strength with old cement, namely cement Padang, Tiga Roda, Holcim and Bosowa which are generally always used in concrete planning at this time.The purpose of this study was to determine the comparison of compressive strength and flexural strength of the concrete and the multiplier between cement Padang, Three Wheels and Conch at 28 days of age. In this study using the method SNI 03-2834-2000. With cylindrical test specimens (150 mm x 300 mm) and size beams (150 mm x 150 mm x 600 mm) three specimens were made for each cement.The maximum concrete compressive strength is found in Padang cement with a compressive strength of 45.86 Mpa, for the minimum compressive strength found in Tiga Roda cement with compressive strength value of 40.19 Mpa and for the compressive strength of cement Conch there is a second with compressive strength value 42.84 Mpa. From the explanation above, the results of 28 days of concrete compressive strength with each cement brand still not reached the planned concrete compressive strength of 38 MPa. The maximum concrete flexural strength is found in Padang cement with a flexural strength value of 5.03 Mpa, for a minimum flexural strength value found in Tiga Roda cement with a flexural strength value of 3.96 Mpa and for the value of Conch cement compressive strength there is a second with flexural strength 4.43 Mpa. From the explanation above, the results of 28 days of concrete flexural strength with each cement brand that has not reached the 4.4 Mpa plan, namely the three-wheeled cement brand.


2021 ◽  
Vol 2 (1) ◽  
pp. 46-54
Author(s):  
Neti Rahmawati ◽  
Irwan Lakawa ◽  
Sulaiman Sulaiman

Concrete is one of the most widely used building materials today interms of physical construction. Concrete is made from a mixture offine, coarse aggregate, cement, and water with a certain ratio, aswell as materials that are usually added to the concrete mixtureduring or during mixing, to changing the properties of concrete tomake it more suitable in certain jobs and more economical, can alsobe added with certain other mixed materials as needed if deemednecessary. Seashells can be used to mix concrete. This study aims todetermine whether the addition of shells aggregate shells in aconcrete mixture can affect the mechanical properties of concrete.The specimens used are in the form of cubes with a size of 15cm x 15cm x 15 cm, consisting of additional concrete coarse and fineaggregate with shell substitution percentage of 0%, 15%, 20% with atotal sample of 45, with the planned concrete quality of K225. Theuse of sea shells in increasing the compressive strength of concrete isbetter used as fine aggregate than coarse aggregate. The use of seashells as a substitute for fine aggregates achieves maximum resultsat 20% composition.


CI-TECH ◽  
2020 ◽  
Vol 1 (01) ◽  
pp. 45-48
Author(s):  
Triaswati ◽  
Srie Subekti ◽  
Sulchan Arifin ◽  
Febri Aditya

Stone dust nowadays is a side product of the stone crushing industry, the quality of which is quite a lot that it becomes a waste that needs to be handled. This study is intended to find out the composition of stone dust by adding some additive substance type D and type F to reach a compressive strength of 350 kg/cm2. The variation of percentage of stone dust on the composition of concrete mixture is 0%, 20%, 40%, 60%, 80%, 100%. The design of concrete mixture composition refers to the procedure of making preparation of the normal concrete mixture. SNI 03-2384-1993. The size of the cylinder test object is 15 cm in diameter and 30 cm in height. The result of this research shows that the mixture using stone dust has quite an effect on the compressive strength of concrete. From the result of the experiment, it is shown that for compressive strength of 350 kg/cm2, we can use 100% of stone dust with a resulted compressive strength of 445 kg/cm2.


Jurnal CIVILA ◽  
2018 ◽  
Vol 3 (2) ◽  
pp. 192
Author(s):  
Ahmad Ridwan ◽  
Annisa Chandra

Concrete is an important element in a construction. The strength of the concrete is determined by the quality of the concrete. So that the mixture used must meet the standards, by using selected materials and adding other substances, it will produce a higher quality than SNI. Masterpozzolith® 402R additive is a mixture of concrete material that serves as a bonding enhancer on concrete, this material will react with cement and water so that when the element is fused it will produce a better bond between coarse and fine aggregates. In this study concrete will use lumajang sand and add the masterpozzolith® 402R additive as an additional material to achieve the desired high quality. with a concrete job mix using the K-200, it is expected to produce concrete with a quality above the specified target. The results of this study can include more than the targets that have been determined, with planning to use mutubeton K-200 the concrete produced can reach K-222, so the method is quite good when applied in construction.


2019 ◽  
Vol 6 (2) ◽  
pp. 145
Author(s):  
Budiman Budiman

Concrete waste from building construction can cause problems for the environment [1]. The use of fine aggregates from concrete waste can be a solution. The purpose of this study is to determine the value of aggregate characteristics and the value of concrete compressive strength from the utilization of concrete waste as substitution fine aggregate use the DOE (department of environment) method and referring to standards SNI. This study used 50% and 60% waste mortal substitution on sand. The results showed that the characteristics of fine aggregate and coarse aggregate met the characteristic requirements for fineness modulus sand of 2.65 (Zone 2) while the aggregate was roughly 6.44 (Zone 3). The value of compressive strength with 50% and 60% concrete waste substitution each obtained the value of characteristic compressive strength of 57.24 kg / cm² and 101.03 kg / cm². The value of using mortar waste as fine aggregate substitution gives a positive value to the quality of concrete. This is evidenced increase in the value of 14.89% in concrete waste substitution 60%.


Author(s):  
H J G M Derks ◽  
V Borrias-Van Tongeren ◽  
A M Bouma ◽  
J C Koedam

The selective removal from 2-amino-2-methyl-l-propanol solutions of impurities that inhibit alkaline phosphatase activity by means of Amberlite chromatography is described. The effects of buffer concentration, column dimensions, adsorbent type, and zinc sulphate addition were investigated. The method was found to improve greatly the quality of commercial 2-amino-2-methyl-1-propanol solutions and to have several advantages over alternative purification methods.


2007 ◽  
Vol 63 (3) ◽  
pp. 503-517 ◽  
Author(s):  
Hideo OGAWA ◽  
Toyoharu NAWA ◽  
Masayoshi YAMAMOTO
Keyword(s):  

2018 ◽  
Vol 3 (1) ◽  
pp. 55
Author(s):  
Suhendra Suhendra

Aggregate quality is very influential on the strength of the resulting concrete. Both coarse and fine aggregates have various characteristics identified from laboratory test results. This study aims to examine the use of various aggregates for a quality of concrete. The coarse aggregate and the fine aggregate used are obtained from the nearest location to the work to be performed. The quality of the concrete reviewed is K-125, K-175 and K-225. The coarse aggregates used are 1-2 size (in cm), 2-3 size (in cm) crushed aggregate and coral. The fine aggregates used for each of the coarse aggregates are also different. The results showed that the coral aggregate did not meet the gradations of concrete aggregate. While the fine aggregate does not meet the gradation of concrete aggregate for the three types used. The concrete compressive strength test results show the use of coarse aggregates of 2-3 size of crushed and coarse aggregate of corals giving the average compressive strength value required for all planned concrete strength. While concrete using coarse aggregates of rocks of size 1-2 only meet the specified compressive strength, but does not meet the required compressive strength.Key words: Aggregates, concrete, compressive strength


10.29007/x8wb ◽  
2018 ◽  
Author(s):  
Vishal Agrawal ◽  
Pankil Shah ◽  
Arman Gupta ◽  
Rahul Shah

In the view of the expeditious growth of infrastructure around the globe, there is an acute shortage of building materials and also a very stern problem of the disposal of the remaining and continuously generating waste. The demand of natural sand in the construction industry also has magnificently increased resulting in the rapid depletion of the river beds which are the natural sources of sand. Acute shortage of good quality of sand has resulted in to considerable increase in its price ultimately affecting the construction cost. Thus there is a severe need to identify a suitable substitute of sand which is eco-friendly and can be used effectively in construction practices mainly in concrete which requires sand as fine aggregates. An attempt is required to investigate use of some alternative materials to save precious natural resources. The current study focuses on determining suitability of using quarry dust, which is a waste product from quarry, as fine aggregates in traditional concrete. During the tenure of the study, some physical and engineering properties of quarry dust and sand were determined and compared. The compressive strength of concrete was determined after replacing sand with quarry dust in various ratios. The results of the study showed encouraging results for replacement of 50% of sand with quarry dust.


Sign in / Sign up

Export Citation Format

Share Document