scholarly journals One-Part Plastic Formable Inorganic Coating Obtain from Alkali-Activated Slag /Starch(CMS) Hybrid Composites

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 844 ◽  
Author(s):  
Xuesen Lv ◽  
Yao Qin ◽  
Zhaoxu Lin ◽  
Zhenkun Tian ◽  
Xuemin Cui
Keyword(s):  
Adhesive Strength ◽  
Hybrid Composites ◽  
Setting Time ◽  
Drying Shrinkage ◽  
Plastic Viscosity ◽  
Strength Development ◽  
Cracking Behavior ◽  
Study Results ◽  
Inorganic Coating ◽  
Alkali Activated

Coating technology can be applied to decorate building constructions. Alkali-activated materials (AAM) are promising green and durable inorganic binders which show potential for development as innovative coating. In the paper, the possibility of using AAM composited with starch (CMS) as a novel plastic formable inorganic coating for decorating in building was investigated. The rheological properties, including plastic viscosity, yield stress, and thixotropy were considered to be critical properties to obtain the working requirements. Four different mixtures were systematically investigated to obtain the optimum formulation, and then were used to study their hardened properties, such as mechanical strengths (compressive, flexural, and adhesive strength), drying shrinkage, cracking behavior, and microstructure. Study results found that CMS could quickly and efficiently be hydrolyzed in an alkaline solution to produce organic plastic gel which filled in AAM paste, leading to the significant improvement of coating consistency, plastic viscosity, and thixotropy. The optimum coating composited with 15.40 wt% CMS shows a relatively stable rheological development, the setting time sufficient at higher than 4 h. Furthermore, CMS shows a significant positive effect on the cracking and shrinkage control due to padding effect and water retention of CMS, which results in no visible cracks on the coating surface. Although the mechanical strength development is relatively lower than that of plain AAM, its value, adhesive strength 2.11 MPa, compressive strength 55.09 MPa, and flexural strength 8.06 MPa highly meet the requirements of a relevant standard.

scholarly journals Effects of Shrinkage Reducing Agent and Expanded Cement on UHPC Fluidity, Mechanical Properties, and Shrinkage Performance

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Tingyu Wang ◽  
Jianqing Gong ◽  
Bo Chen ◽  
Xiao Gong ◽  
Hongkui Luo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Setting Time ◽  
Autogenous Shrinkage ◽  
Drying Shrinkage ◽  
Reducing Agent ◽  
Strength Development ◽  
Study Results ◽  
Binder Ratio ◽  
Early Strength ◽  
Shrinkage Reducing Agent

The purpose of this study was to evaluate the effects of a shrinkage reducing agent (SRA) and Portland expanded cement (PEC) on the fluidity, mechanical properties, and shrinkage performance of ultrahigh-performance concrete (UHPC). The results indicated that the fluidity of the fresh UHPC mortar initially decreased and then increases along as a function of SRA dosage. When the dosage of SRA was 1%, the UHPC mortar fluidity was at its minimum. For dosages exceeding 1%, the additional water-binder ratio of the mortar increased, which in turn increased the UHPC fluidity. That is, the SRA delayed the cement hydration and increased the setting time, which is not conducive for early strength development of UHPC. As the SRA dosage was increased (i.e., 0%–2%), the autogenous shrinkage of UHPC decreased significantly such that even a small dosage of about 0.5% SRA was able to effectively reduce drying shrinkage. From the study results, it was also observed that PEC accelerated the loss of fluidity in the fresh UHPC and concurrently promoted the early strength development of UHPC. At 75% PEC content, the strength enhancement effects tended to be stable. This means that although the addition of PEC will potentially increase the autogenous shrinkage of UHPC, it has the positive effect of inhibiting drying shrinkage provided that the PEC dosage is controlled within the 25%–50% range. Furthermore, morphological analyses using a scanning electron microscope (SEM) indicated that an increase in the SRA dosage loosens the UHPC microstructure, with the formation of the hydration products remaining incomplete, thus ultimately causing the UHPC strength to decrease. Overall, the study findings indicated that 2% SRA and 25%–50% PEC can effectively reduce the shrinkage of UHPC and are, therefore, recommended as the optimum dosages.

scholarly journals Effects of Light-Burnt Dolomite Incorporation on the Setting, Strength, and Drying Shrinkage of One-Part Alkali-Activated Slag Cement

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2874 ◽  
Author(s):  
In Kyu Jeon ◽  
Jae Suk Ryou ◽  
Sadam Hussain Jakhrani ◽  
Hong Gi Kim
Keyword(s):  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Setting Time ◽  
Drying Shrinkage ◽  
Slag System ◽  
Strength Development ◽  
Alkali Activated Slag ◽  
Granulated Blast Furnace Slag ◽  
Activated Slag ◽  
Alkali Activated

This study investigates the potential of light-burnt dolomite (LBD) as a supplementary cementitious material with ground granulated blast furnace slag (GGBFS) and Ordinary Portland cement (OPC). In this work, LBD was substituted for up to 20% of GGBFS in sodium sulfate-activated slag systems. The effects of LBD incorporation on the flow, setting time, compressive and flexural strength development, and drying shrinkage were explored with, X-ray diffraction and thermogravimetric analyses. LBD incorporation resulted in greater strength development of an alkali-activated slag system. The optimum LBD content for strength development was 10%, regardless of ordinary Portland cement content. In addition, LBD decreased the drying shrinkage, accelerated the hydration process, and induced hydrotalcite formation, which can be attributed to the reactive MgO inside LBD.

Effect of Alkali-Activators on the Strength Development and Drying Shrinkage of Alkali-Activated Binder

2012 ◽  
Vol 482-484 ◽  
pp. 1012-1016
Author(s):  
Mao Chieh Chi ◽  
Jiang Jhy Chang ◽  
Ran Huang ◽  
Zai Long Weng
Keyword(s):  
Ph Value ◽  
Setting Time ◽  
Drying Shrinkage ◽  
Strength Development ◽  
Modulus Ratio ◽  
Alkali Activated Slag ◽  
Key Factor ◽  
Activated Slag ◽  
Portland Cement Paste ◽  
Alkali Activated

The purpose of this study is to investigate the effect of various contents and modulus ratios of alkali activators on strength development and drying shrinkage of alkali-activated slag pastes. Experimental results show that the alkali-modulus ratio is the key factor influencing pH value and drying shrinkage. The lower the alkali-modulus ratio is, the higher the pH value is, and the lower the drying shrinkage is. In addition, the increase of the amount of alkali-activators decreases the initial and final setting time. The compressive strength of alkali-activated slag pastes is higher than that of Portland cement paste at all ages.

scholarly journals Alkali-activated laterite binders: Influence of silica modulus on setting time, Rheological behaviour and strength development

2021 ◽  
pp. 100175
Author(s):  
Cyriaque Rodrigue Kaze ◽  
Adeyemi Adesina ◽  
Gisèle Laure Lecomte-Nana ◽  
Thamer Alomayri ◽  
Elie Kamseu ◽  
...  
Keyword(s):  
Setting Time ◽  
Rheological Behaviour ◽  
Strength Development ◽  
Alkali Activated

scholarly journals Positive Influence of Liquid Sodium Silicate on the Setting Time, Polymerization, and Strength Development Mechanism of MSWI Bottom Ash Alkali-Activated Mortars

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1927
Author(s):  
Lei Jin ◽  
Guodong Huang ◽  
Yongyu Li ◽  
Xingyu Zhang ◽  
Yongsheng Ji ◽  
...  
Keyword(s):  
Sodium Silicate ◽  
Setting Time ◽  
Bottom Ash ◽  
Free Water ◽  
Polymerization Reaction ◽  
Liquid Sodium ◽  
Strength Development ◽  
Mswi Bottom Ash ◽  
Alkali Activated ◽  
Development Mechanism

Setting time and mechanical properties are key metrics needed to assess the properties of municipal solid waste incineration (MSWI) bottom ash alkali-activated samples. This study investigated the solidification law, polymerization, and strength development mechanism in response to NaOH and liquid sodium silicate addition. Scanning electron microscopy and X-ray diffraction were used to identify the formation rules of polymerization products and the mechanism of the underlying polymerization reaction under different excitation conditions. The results identify a strongly alkaline environment as the key factor for the dissolution of active substances as well as for the formation of polymerization products. The self-condensation reaction of liquid sodium silicate in the supersaturated state (caused by the loss of free water) is the major reason for the rapid coagulation of alkali-activated samples. The combination of both NaOH and liquid sodium silicate achieves the optimal effect, because they play a compatible coupling role.

scholarly journals Effect of calcium-rich compounds on setting time and strength development of alkali-activated fly ash cured at ambient temperature

2018 ◽  
Vol 9 ◽  
pp. e00198 ◽  
Author(s):  
Prinya Chindaprasirt ◽  
Tanakorn Phoo-ngernkham ◽  
Sakonwan Hanjitsuwan ◽  
Suksun Horpibulsuk ◽  
Anurat Poowancum ◽  
...  
Keyword(s):  
Fly Ash ◽  
Ambient Temperature ◽  
Setting Time ◽  
Strength Development ◽  
Alkali Activated

scholarly journals Alkali-Activated Hybrid Concrete Based on Fly Ash and Its Application in the Production of High-Class Structural Blocks

Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 946
Author(s):  
Oriana Rojas-Duque ◽  
Lina Marcela Espinosa ◽  
Rafael A. Robayo-Salazar ◽  
Ruby Mejía de Gutiérrez
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Modulus ◽  
Setting Time ◽  
Modulus Of Rupture ◽  
Strength Development ◽  
Block Type ◽  
High Class ◽  
Structural Blocks ◽  
Alkali Activated

This article reports the production and characterization of a hybrid concrete based on the alkaline activation of a fly ash (FA) of Colombian origin, which was added with 10% Portland cement (OPC) in order to promote the compressive strength development at room temperature. The alkali-activated hybrid cement FA/OPC 90/10 was classified as a low heat reaction cement (type LH), according to American Society of Testing Materials, ASTM C1157; the compressive strength was of 31.56 MPa and of 22.68 MPa (28 days) at the levels of paste and standard mortar, respectively, with an initial setting time of 93.3 min. From this binder, a hybrid concrete was produced and classified as a structural type, with a compressive strength of 23.16 MPa and a flexural modulus of rupture of 5.32 MPa, at 28 days of curing. The global warming potential index (GWP 100), based on life cycle analysis, was 35% lower than the reference concrete based on 100% OPC. Finally, its use was validated in the manufacture of a solid block-type construction element, which reached a compressive strength of 21.9 MPa at 28 days, exceeding by 40.6% the minimum strength value established by the Colombia Technical Standard, NTC 4026 (13 MPa) to be classified as high class structural blocks.

CERAMIC WASTE POWDER AS SUPPLEMENTARY CEMENTING MATERIAL IN CONCRETE MIXTURES

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Amr S. El-Dieb ◽  
Dima M. Kanaan
Keyword(s):  
Solid Waste ◽  
Setting Time ◽  
Drying Shrinkage ◽  
Strength Development ◽  
Hardened Concrete ◽  
Ceramic Tiles ◽  
Chloride Permeability ◽  
Ceramic Waste ◽  
Alternative Ingredient ◽  
Cementing Material

Green environment is a challenging concern to accomplish in today’s world. This could be achieved through a beneficial recycling procedure by reusing solid waste materials. Ceramic tiles are widely used in most structures; its production creates waste powder. Concrete that contains solid waste is referred to as “Green” concrete. Using ceramic waste powder (CWP) as an alternative ingredient in concrete will have a positive environmental impact furthermore will help reserve natural resources. In this study CWP will be investigated as supplementary cementing material (SCM) in making concrete. The ceramic waste powder will be used as SCM with different dosages replacing cement. The effect of ceramic waste powder as SCM on the properties of fresh concrete will be investigated such as slump, slump loss and setting time. The properties of hardened concrete will be assessed through compressive strength development, drying shrinkage and durability characteristics was evaluated by rapid chloride permeability test (RCPT) and bulk electrical resistivity. Test results show that CWP can be used as SCM in making concrete. The outcomes of the study shed light on how CWP could be utilized effectively as an alternative ingredient of concrete and the optimum dosage for use which will result in an effective way for using solid waste and protecting the environment.

scholarly journals Influences of Sodium Lignosulfonate and High-Volume Fly Ash on Setting Time and Hardened State Properties of Engineered Cementitious Composites

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4779
Author(s):  
Anggun Tri Atmajayanti ◽  
Chung-Chan Hung ◽  
Terry Y. P. Yuen ◽  
Run-Chan Shih
Keyword(s):  
Fly Ash ◽  
Setting Time ◽  
Autogenous Shrinkage ◽  
Drying Shrinkage ◽  
High Volume ◽  
Cementitious Composites ◽  
Sodium Lignosulfonate ◽  
Engineered Cementitious Composites ◽  
Cracking Behavior ◽  
Setting Times

Engineered Cementitious Composites (ECC) exhibit high ductility accompanied by multiple narrow cracking behavior under uniaxial tension. The study experimentally investigated the influence of sodium lignosulfonate and high volumes of fly ash (HVFA) on the properties of fresh and hardened ECC, with the experimental variables including the amounts of fly ash, polyvinyl alcohol (PVA) fibers, and sodium lignosulfonate. The test results were discussed extensively in terms of the initial and final setting times, compressive and tensile behavior, and drying and autogenous shrinkage. The results indicated that the initial and final setting times of ECC were increased along with the sodium lignosulfonate content of up to 1%. The drying shrinkage development was governed by the first 14 days. In addition, the major autogenous shrinkage developed for more than 28 days. The amounts of fly ash, PVA fibers, and sodium lignosulfonate considerably impacted the autogenous shrinkage. Moreover, it was found that the dosage of sodium lignosulfonate at 0.5% of the weight of Portland cement optimally reduced the shrinkage and enhanced the tensile strain capacity for ECC.

Sign in / Sign up

Export Citation Format

Share Document