Concrete Binder Research Articles

NDT Monitoring of Alkali-Activated Material Carbonation

Production of Portland cement is relatively environmentally demanding (high CO2 emissions, extraction of raw materials for its production). Alkali-activated materials are an alternative to conventional Portland cement in the production of concrete. For alkali-activated binder concretes, their ability to withstand corrosive environments and their ability to protect steel reinforcement must be assessed. It is also necessary to know the suitability of non-destructive methods for monitoring the degradation process of these concretes. The paper deals with the carbonation monitoring of concrete with alkali-activated binder (slag) by the impact-echo method. Slag activated by sodium hydroxide (NaOH) was used as a binder. The specimens were tested by the non-destructive method (Impact-echo, ultrasound velocity). We focused on the shift of the dominant frequency obtained by the Impact-echo method.

Engineering and gamma-ray attenuation properties of steel furnace slag heavyweight concrete with nano calcium carbonate and silica

As the nuclear energy sector continues to grow worldwide, the improvement of concrete’s radioactive isolation properties for preserving both the environment and human lives in nuclear power plant applications has received a global interest among researchers. Although nano-silica, nano-calcium carbonate, and steel furnace slag have high molar mass and favorable physical properties to improve the concrete’s radioactive insulation properties, scarce literature on the subject matter has been published. The goal of this study is to investigate the appropriateness of using nanomaterials such as nano-silica slurry and nano-calcium carbonate as additives for the production of steel furnace slag (aggregate of steel furnace slag: ASFS)-based heavyweight concrete (HWC) with improved durability, mechanical strength, and gamma (γ)-ray attenuation properties. A new contribution of the study is the use of nano-SiO2 slurry and nano-CaCO3 in concrete binder formulation to enhance concrete gamma-ray shielding capability. An optimized content was developed for the nano calcium carbonate, in combination with a constant amount of nano-silica slurry, to improve the performance of the HWC. An investigation program was implemented with eight concrete mixes, which were prepared by utilizing ASFS as the main aggregate with 3% of nano-silica slurry in combination with (0–3%) of nano-calcium carbonate as additives to produce high strength HWC. The hardened concrete samples were evaluated for mechanical strength, fluid transport and γ-ray shielding properties. The effect of 3% nano-SiO2 slurry and 2.0% nano-CaCO3 on the compressive strength and gamma-ray shielding increased by 10.3 and 3.4%, respectively, at 28 days as compared to the control mix without nanomaterials additives. The other mechanical and fluid transport properties of the concrete were also improved significantly. In conclusion, the combined use of nano-silica slurry and nano-calcium carbonate would enhance the mechanical strength, fluid transport and γ-ray shielding properties of steel furnace-slag heavyweight concrete.

Influence of coconut shell ash on workability, mechanical properties, and embodied carbon of concrete.

The significant contribution of the carbon dioxide emission from the production of Portland cement which is the main binder used in concrete has called for an imminent need to find environmentally friendly materials as alternatives. The availability of large quantities of agricultural wastes such as coconut shell in most developing countries opens a pathway to explore how these materials can be recycled into concrete as the binder composition. The combustion of most solid agricultural wastes results in the production of ash which can be used to replace Portland cement as a binder in concrete. This paper presents the results from the experimental investigation of the effect of coconut shell ash on the workability, mechanical properties, and embodied carbon of concrete. A total of five mixtures were made with coconut shell ash replacing Portland cement up to 20%. Results from this paper showed that coconut shell ash can be incorporated into concrete mixtures to reduce its embodied carbon. A reduction in embodied carbon of about 15% was achieved when 20% of Portland cement was replaced with coconut shell ash. The incorporation of coconut shell ash into concrete mixtures also resulted in an increase in the mechanical properties up to 10% replacement of Portland cement. The compressive, tensile, and flexural strength of mixtures incorporating 10% coconut shell ash as replacement of Portland cement is 12%, 10%, and 9% higher than that of the control mixture without coconut shell ash.

Analysis the use of steel slag as a replacement of natural aggregate in the asphalt concrete binder course (AC-BC) mixture

Aggregates are the largest component of the flexible pavement structure. The quality of the road is largely determined by the nature and type of aggregates used. Currently, the development of road infrastructure in Indonesia continues to experience increasing amount of natural aggregate use, so this will cause the availability of natural aggregate raw materials to continue to thin out. For that reason, an effort should be made to find alternatives to the use of natural aggregates, one of which is the utilization of steel slag. In this study, it will be examined the characteristics of the steel slag aggregates by referring to the 2018 Bina Marga specifications and the Marshall characteristic test method. This study used steel slag addition with variations of 0%, 50%, 80% and 100%. The results obtained in this study are that the value characteristics of the slag aggregate meet the standard specifications. The use of steel slag at 80% variation in coarse aggregate produces the best stability value which is equal to 2320,19 Kg. Overall, the use of steel slag can be an alternative to the use of natural aggregates. Moreover, steel slag can also be an alternative to an effort to reduce waste.

Permeability of self-compacting concrete made with recycled concrete aggregates and Portland cement-fly ash-silica fume binder

Permeability properties of self-compacting concrete (SCC) made with fine recycled concrete aggregates (FRCA), coarse recycled concrete aggregates (CRCA), and Portland cement-fly ash-silica fume binder are reported. Fresh and permeability properties of various SCC mixes were assessed. The results indicate that the increase in content of fine and coarse recycled concrete aggregates (RCA) in SCC tends to deteriorate the workability and permeability properties. The compressive strength also decreased with the inclusion of RCA. The substitution of 50% CRCA and 25% FRCA in SCC mix shows marginal decrease in hardened SCC properties as compared to SCC made with fine and coarse natural aggregates. Further, increase in FRCA content in SCC mix deteriorated the compressive strength and permeability properties. Furthermore, the addition of SF at 10% by weight of ordinary Portland cement was able to compensate the loss of permeability properties even for 50% substitution of both FRCA and CRCA.

Feasibility study of the properties of geopolymer concrete with ferrochrome slag and silica fume

The special attention of this paper relates to the usage of ferrochrome slag (FS) or charge chrome as coarse aggregate and silica fume (SF) as a binder in the fly ash geopolymer concrete (GPC) mixes. In this, a varying percentage of charge chrome and SF has been used. The replacement of natural coarse aggregates produced twenty GPC mixtures with 0 to 40% FS and fly ash with 0 to 15% SF. This investigation comprises of the determination of workability, compressive strength (CS) after 7, 14 and 28 days of curing. Ultrasonic pulse velocity (USPV), rebound number, water absorption, and density have been investigated to evaluate the combined impact of FS and SF on the properties of GPC. The results of this research revealed that the slump values were decreased with the addition of SF in FS based GPC. The USPV and rebound number are the non-destructive tests of GPC followed similar trends as that of compressive strength. At the higher percentage of Silica fume in GPC mixes, water absorption was also increased. The F30S10 sample i. e 30% charge chrome and 10% silica fume showed optimum performance.

Performance and sustainability overview of alkali-activated self-compacting concrete

Self-compacting concrete (SCC) has gained huge attention recently due to its high workability which eliminates the need for vibration and makes its placement easier compared to conventional concrete. However, the production of Portland cement (PC) which is the main binder in SCC is energy-intensive and one of the major contributors to the world’s carbon dioxide emission. On the other hand, the use of alkali-activated binders (AABs) in concrete has been reported to reduce the energy consumption and carbon emission of concrete by more than 50%. Therefore, the use of AAB as a binder in SCC can help to achieve an eco-friendlier concrete. This paper gives a short overview of the performance of SCC made with AABs. The effect of various factors on the performance of alkali-activated self-compacting concrete (AASCC) was discussed and a simplified sustainability assessment of AASCC was carried out. Discussions from this paper showed that AASCC with acceptable fresh and hardened properties can be achieved with the proper selection of materials. In addition, the evaluation of the embodied energy and carbon of different types of concrete showed that AASCC is more sustainable. However, more research in this field is required to encourage its universal acceptance and large-scale application.

Performance evaluation of polypropylene fiber waste reinforced concrete in presence of silica fume

Abstract The worldwide application of high-performance concrete is particularly suitable for high-level towers, long bridges and special structures. Concrete binder products (used in high-level concrete), due to their low expense, reliability and ample compression strength in the structural framework, are desirable for use as construction materials. Failure is attributed to its features of poor tensile strength and effect and its sensitivity to increases in moisture. The fiber reinforcement can be a simple, functional and cost-effective way to resolve such limitations. The application of fibers as concrete reinforcement will improve many of its properties, in particular strength, fatigue, permeability, and barrier properties. Various consequences of the addition of silica fume (SF) and polypropylene fiber waste (PFW) to the mechanical characteristics of the concrete have been analyzed in this study. The current study aimed at analyzing the effects of cement substitution with SF, PFW and their combinations. SF content was ranged between 4%, 8%, 12%, and 16% and PFW as 0.4%, 0.8%, 1.2% and 1.6% by weight substitution of cement in order to analyze the effect on workability, compressive strength & tensile strength investigated at 7 days, 28 days, & 90 days of curing ages. The efficiency of the concrete w.r.t mechanical properties was improved severalfold in ternary composites. The XRD and SEM assessment correlated the microstructure with the improved mechanical properties of the composites.

PROPERTIES OF CONCRETE CONTAINING BLENDED CEMENT AND LIGHTWEIGHT ARTIFICIAL AGGREGATE

The limitation of natural resources and the increase in industrial waste materials have been being the main concern in many developing countries. Therefore, many studies have been conducted to investigate the feasibility of industrial by-products to be used as artificial aggregate in concrete manufacturing. This study examined the influences of using artificial materials as aggregate replacement of natural aggregate and active pozzolana cement as a binder in concrete. Numbers of tests were performed to investigate the fresh and hardened concrete properties in terms of workability, density, expansion and shrinkage, ultrasonic pulse velocity, flexural strength, compressive strength and mode of failure. The specimens consist of cube and prism were prepared and tested after 3, 7 and 28 days of water curing and air curing. Results of concrete with artificial aggregates recorded lower workability due to the high water absorption, lower density of concrete, lower drying shrinkage due to the reduced free water content and lower pulse velocity in concrete. However, the compressive and flexural strengths were improved by 10% and 38% as of normal concrete, respectively. Therefore, the results obtained from this study indicated that the artificial aggregates and pozzolan cement used have positive effects on concrete properties.

PROPERTIES OF CONCRETE CONTAINING BLENDED CEMENT AND LIGHTWEIGHT ARTIFICIAL AGGREGATE

The limitation of natural resources and the increase in industrial waste materials have been being the main concern in many developing countries. Therefore, many studies have been conducted to investigate the feasibility of industrial by-products to be used as artificial aggregate in concrete manufacturing. This study examined the influences of using artificial materials as aggregate replacement of natural aggregate and active pozzolana cement as a binder in concrete. Numbers of tests were performed to investigate the fresh and hardened concrete properties in terms of workability, density, expansion and shrinkage, ultrasonic pulse velocity, flexural strength, compressive strength and mode of failure. The specimens consist of cube and prism were prepared and tested after 3, 7 and 28 days of water curing and air curing. Results of concrete with artificial aggregates recorded lower workability due to the high water absorption, lower density of concrete, lower drying shrinkage due to the reduced free water content and lower pulse velocity in concrete. However, the compressive and flexural strengths were improved by 10% and 38% as of normal concrete, respectively. Therefore, the results obtained from this study indicated that the artificial aggregates and pozzolan cement used have positive effects on concrete properties.

Bond behaviour between steel / stainless-steel reinforcing bars and low binder concrete (LBC)

Reducing the cement content of concrete is of paramount importance towards sustainability, since its production process is highly energy-consuming and delivers massive CO2 emissions to the atmosphere. In this paper, the bond behaviour between steel and stainless-steel reinforcing bars and Low Binder Concrete (LBC), produced with approximately one half and almost one fourth of the minimum cement content prescribed in the standards, is experimentally investigated. Results show the compactness of the mixture to be the main parameter controlling bond development, more than the mixture compressive strength as suggested in published results and standards. A more compact and denser mixture increases the contact surface between the reinforcing bars and concrete, improving friction between both. LBC mixtures with lowered cement content, up to almost one fourth of the minimum recommended, can be used without jeopardizing the bond strength of reinforcing bars. LBC mixtures promise to be a fitting approach towards greater sustainability in the concrete production sector.

Utilization of Polycrete in Manufacturing Manhole Covers: A Comparative Study

Sultanate of Oman focuses on its infrastructure development in the most sophisticated planning manner by preserving its precious landscape and terrains. Cities like Muscat, Al-Amerat, Sohar, etc. are now in high priority in its infrastructure development. Drainage and sewerage network play a vital role for cities and country's infrastructure development. The ETP (Enlarged Treatment Plant) or STP (Sewerage Treatment Plant) is very important to treat the industrial and domestic waste water and the conveyance of waste water flows through network of pipes, manholes and chambers. Portland or sulfur resistant cement concrete products were used to convey the waste water. But, the durability is a question for long term development plan due to corrosive effect on the product and give way for more renovation or rehabilitation program for the entire network which needs a re-budgeting plan. While an alternative and high corrosive resistant and durable product, polymer concrete products offer the best solution to avoid or eliminate renovation process for the network. As a result of its development over time, polymerized monomer can substitute Portland cement as a binder in concrete. Polymer concrete holds multiple effective properties to traditional concrete using Portland cement, such as high compressive strength, low permeability, resistance to corrosive agents as well as chemicals, and rapid curing. These properties provided polymer concrete with many uses in extremely specific sectors around the globe. This research is discussing the various types of Polycrete, assessing polycrete’s rheological properties and the properties of the normal cement used instead of Polycrete, comparing normal and Polycrete cement as well as analyze the environmental issues and the price of using Polycrete instead of normal cement

Mechanical and durability properties of magnesium silicate hydrate binder concrete

Mechanical and durability properties of concrete made with magnesium–silicate–hydrate (M–S–H) binder systems were tested in comparison with Portland cement. The M–S–H binary binder system included 60% magnesium oxide (MgO) and 40% silicon oxide (SiO2), while the ternary system replaced 10% of the M–S–H binder with 10% crushed quartz filler. It was found that the compressive strength of M–S–H concrete samples at 28 d was approximately 40 MPa with little further increase after this age. The M–S–H concrete had lower tensile strengths and modulus of elasticity than Portland cement control samples. The stress–strain relationship of the M–S–H concrete showed an unusual non-linear relationship at a loading range up to 40% of the compressive strength. The porosity and permeability of concrete using M–S–H binders were higher than Portland cement. The addition of crushed quartz filler was shown to improve microstructure and mechanical and durability properties of M–S–H binder concrete for potential structural applications.

Analisis Karakteristik Marshall pada Beton Aspal Lapis Pengikat (Asphalt Concrete-Binder Course) menggunakan Aspal Modifikasi Serbuk Serat Pelepah Batang Pisang

Asphalt modification by adding fiber powder of banana stem can be implemented to improve the performance of pure asphalt. Asphalt concrete binder course AC-BC is a flexible pavement layer that functions to distribute the load towards the foundation layer. So it really needs strength, durability and stability of the materials. For that, it is necessary to use asphalt modification with fiber powder of banana stem which is used as a binding material in AC-BC asphalt concrete mixture. The proper percentage of modified asphalt level will determine the optimum quality of an asphalt mixture. Asphalt concrete specimens were made in 3 (three) samples for each variation of asphalt level by 5%; 5.5%; 6%; 6.5%; and 7%. The asphalt optimum level in the mixture is carried out through volumetric investigation in the form of VMA, VIM, and VFB values and mechanical assessment in the form of stability, flow and Marshall Quetient. The results of data analysis found that the value of VIM, stability and MQ tend to decrease with increasing levels of modified asphalt. On the other hand the value of VMA, VFB and flow tend to rise with increasing levels of modified asphalt. However, from the five variations of asphalt levels obtained asphalt levels of 5% and 5.5% which meet all the specifications of AC-BC asphalt concrete specification. To determine the asphalt optimum level, the average of qualified asphalt level is taken. So that the asphalt concrete AC-BC will produce a better structural performance at 5.25% asphalt level with banana stem fiber powder on asphalt by 0.1%.

Special Issue Low Binder Concrete and Mortars

It is well known that, after water, concrete and mortars are the most demanded materials worldwide [...]

Experimental Works on Geopolymer Concrete Composites: Destructive and Non-Destructive Testing

The main theme of this research work is to study Geopolymer concrete (GPC) composites behavior when different binding materials in certain percentages are replaced completely with cement in order to analyse the mechanical properties and bonding between aggregates and Geopolymer paste. The term Geopolymer was coined by Professor Davidovits in 1978, a kind of inorganic polymer that can be prepared at room temperature by utilizing modern waste. Any material that contains for the most part silicon (Si) and Aluminium (Al) is a source material for the production of Geopolymer. Geopolymer is an inorganic polymer composites which is an eco-friendly sustainable product by replacing the conventional concrete such as Flyash, Ground Granulated Blast furnace slag (GGBS, Silica fume, Metakaolin(MK) and other siliceous materials are used as substitute binders to Portland cement. The properties of GPC have been studied in several researches due to its importance and ability to solve the problems of ordinary Portland cement. GGBS, MK and Rice Husk Ash (RHA) was used as replacement to cement and binder in Geopolymer concrete. The specimens are cured at ambient temperature condition. Mechanical properties of the GPC mix specimens are studied for different time ages (7days, 21days and 28days) and the strengths of the specimens were determined. Alkaline Activator Solutions are prepared in the molarities of 8, 10.

Features of the Formation of Properties of Stone-Mastic Asphalt Concrete Based on a Warm Polymer Modified Binder

Stone mastic asphalt concrete is one of the main types of asphalt concrete used for the construction of road surfaces. The quality, reliability and longevity of which depends on road safety of vehicles. To reduce the intensity of aging processes occurring at the stage of production and laying of asphalt concrete, "green" technologies are used, based on the use of physical and chemical processes that reduce the viscosity of bitumen to produce warm asphalt mixtures. This paper discusses the features of the formation of properties of crushed stone-mastic asphalt mixes SMA-15 based on polymer bitumen modified, compacted at lower temperatures, relative to traditional asphalt concrete. The influence of chemical additives of domestic and foreign production of DAD-TA and Cecabase RT 945 on the properties of modified binder and asphalt concrete was studied. It was established that they have a positive plasticizing effect on the modified bitumen binder in crushed stone-mastic asphalt concrete without a decrease in heat resistance and adhesive strength, which made it possible to compact asphalt concrete samples at low temperatures (up to 130°C) without negatively affecting the strength and deforming properties of asphalt concrete.

Influence of Surface Texture on Interface Bond Shear Strength of Asphalt Concrete

The bonding strength provided by the tack coat between asphalt concrete layers at the interface is considered as an essential issue in the performance of the flexible pavement throughout its service life. However, the surface texture of the pavement surface exhibits another essential issue in the bond strength. In this investigation, three layers of asphalt concrete (base, binder and wearing) courses with (25, 19, and 12.5) mm of nominal maximum size of aggregates have been prepared using roller compactor. Rapid curing cutback RC-70 and cationic medium setting emulsion CMS have been implemented as tack coats with three application rates. The slab specimens were subjected to mean texture depth determination using sand patch method. Core specimens of 102 mm diameter were obtained from the prepared slab samples and subjected to interface bond strength test with the aid of a special manufactured mold. Test results were analyzed and compared. It was concluded that when RC-70 tack coat was implemented, asphalt concrete binder course laid on base course exhibited the highest shear strength of 1600 kPa at an application rate of 0.33 liter/m2 when compared to other application rates. Asphalt concrete wearing course laid on binder course exhibited the highest shear strength of 1515 kPa at an application rate of 0.15 liter/m2 when compared to other application rates. When CMS tack coat was implemented, asphalt concrete binder course laid on base course exhibited the highest shear strength of 1620 kPa at an application rate of 0.23 liter/m2 when compared to other application rates. Finally, the asphalt concrete wearing course laid on binder course exhibited the highest shear strength of 2272 kPa at an application rate of 0.23 liter/m2 when compared to other application rates.

Studi Pemanfaatan Limbah Beton Mutu Tinggi pada Campuran Asphalt Concrete Binder Course (AC-BC)

The purpose of this research is to find out whether the modification of asphalt used with high quality of concrete waste as coarse substitute aggregate of Asphalt Concrete - Binder Course (AC – BC). In this study, the researcher used high quality of concrete waste fc’ 42, fc’ 47, fc’ 50, each waste concrete quality will be mixed with asphalt bitumen contents 5%, 5.5 %, 6 %, 6.5, and 7%. This research used the Marshall test method to determine stability value, flow value, Void In Mix (VIM), Void In Mineral Aggregate (VMA), Void Filled With Asphalt (VFA). AC - BC with high quality of concrete waste fc'42 obtained for the best bitumen content obtained is 7%, with a stability value of 1491.705 kg, flow 4.264 mm, MQ 343.465, VIM 9.190%, VFA 34.425%, VMA 15.067%. AC - BC with high quality of concrete waste fc'47 was obtained for the best asphalt content obtained was 7%, with stability values ​​1551.715 kg / mm, flow 4.587 mm, MQ 339.122, VIM 5.530%, VFA 63.308%, VMA 14.235%.The best results of the Marshall test were obtained at the high quality of concrete waste fc'50, asphalt content obtained is 7%, with the stability of 1616.145 kg, flow 4.859 mm, MQ 333.720, VIM 5.116%, VFA 55.597%, VMA 13.226%. Referring to the obtained research test, the values of stability match with Bina Marga standard value, namely 800 kg, but VFA value, VIM, and flow are not of Bina Marga standard values. In addition, VMA vales fulfilling Bina Marga standard values are concrete waste fc’42 and fc’47 with the scale 14%. The researcher hopes that this research will be the guideline in making a mixture of asphalt concrete binder courses with the replacement of coarse aggregate using concrete waste and to inspire people in utilizing concrete waste in technical aspects.

Influence of nano TiO2 on strength and durability properties of geopolymer concrete

Geopolymer concrete (GPC) is treated as an ecologically pure construction material because cement is completely retrieved by pozzolanic materials that are abundant in alumina and silica. GPC is actuated with alkaline liquids to begin as a binder in concrete. Geopolymer concrete evince many outstanding properties just as rapid strength, less shrinkage, and less creep, better resistance against sulphate and chloride attacks. The current review is to explore the effect of nano titanium dioxide (nano-TiO 2 ) on fly ash based geopolymer concrete (FAGPC) with oven curing at 60 0 c for 48 hrs. As an initial study, GPC with 10 M was carried out for dissimilar ratios of sodium silicate (Na 2 SiO 3 ) to sodium hydroxide (NaOH) solutions between 1.5 and 3.5. Out of all mixes, alkaline activator ratio harmonize to the highest compressive strength was ascertained at 2.5. This ratio was kept constant for further study in GPC carried out by replacing fly ash with nano TiO 2 between 1% and 5%. For all mixes of GPC with and without nano titanium dioxide, mechanical and durability properties were observed and evaluated. The test results depict that, percentage increase of nano TiO 2 , gives rise to decline in workability and improves strength properties of concrete. The maximum strength enrichment was noticed when 5% of nano-TiO 2 was incorporated in GPC. As percentage of nano TiO 2 hiked in GPC, the results of RCPT, Water absorption and Sorptivity decreased. All these GPC specimens are immersed individually in 5% magnesium sulphate and 5% sodium chloride to know the resistance of geopolymer concrete against sulphate and chloride attacks. Results of this study concluded that increase in nano TiO 2 percentage gives better performance against sulphate and chloride solutions. Change in microstructure and mineral phases of reference geopolymer concrete samples and maximum strength obtained geopolymer concrete samples containing nano TiO 2 was investigated using SEM and XRD analyses.