Effects of the incorporation of residue of masonry on the properties of cementitious mortars

This paper presents results of an experimental study of a residue of masonry (RM), sampled from a construction and demolition waste (CDW), added as a supplementary cementitious material (SCM) to partially replace up to 50% of Portland cement in the preparation of mortars. The pozzolanic activity (fixed lime and strength activity index), setting time, heat of hydration, the (autogenous and drying) shrinkage and compressive strength tests were carried out. The results show how the RM has a positive activity because the increase of RM replacement level in the mortars generates a lower heat of hydration and autogenous and drying shrinkage. The fixed lime at 28 and 180 days, indicating that the RM exhibits in some degree pozzolanic activity and the Strength Activity Index (SAI) was 77.13% and 84.36% of the compressive strength of 100% OPC mortar at the 7 and 28 days respectively, which conformed to ASTM C311. These results indicate that RM should be considered appropriated for using as a supplementary cementitious material.

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Testing the Supplementary Cementitious Material Based on GGBFS and Zeolite for Prediction of the Activity Index

Proceedings ◽

10.3390/proceedings2201287 ◽

2018 ◽

Vol 2 (20) ◽

pp. 1287

Author(s):

Marek Kovac ◽

Alena Sicakova ◽

Matej Spak

Keyword(s):

Blast Furnace ◽

Blast Furnace Slag ◽

Activity Index ◽

Setting Time ◽

Cementitious Material ◽

Supplementary Cementitious Material ◽

Initial Setting Time ◽

Granulated Blast Furnace Slag ◽

Initial Setting ◽

Furnace Slag

The article deals with cement supplementary materials based on ground granulated blast furnace slag and zeolite. Purpose of the experiment was to observe dependences (if they exist) between selected parameters (modulus of basicity, modulus of hydraulicity and initial setting time) and activity indexes, for easier and quicker way to determine or predict the activity index. Testing showed that moderate dependences between those parameters and activity indexes were observed. Results showed that prediction of activity indexes based on chemical composition is feasible.

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Characterization and Hydration Mechanism of Ammonia Soda Residue and Portland Cement Composite Cementitious Material

Materials ◽

10.3390/ma14174794 ◽

2021 ◽

Vol 14 (17) ◽

pp. 4794

Author(s):

Dong Xu ◽

Pingfeng Fu ◽

Wen Ni ◽

Qunhui Wang ◽

Keqing Li

Keyword(s):

Compressive Strength ◽

Building Materials ◽

Setting Time ◽

Cement Composite ◽

Cementitious Materials ◽

Heat Of Hydration ◽

Cementitious Material ◽

Cement Industry ◽

Hexagonal Plate ◽

Hydration Mechanism

The use of ammonia soda residue (ASR) to prepare building materials is an effective way to dispose of ASR on a large scale, but this process suffers from a lack of data and theoretical basis. In this paper, a composite cementitious material was prepared using ASR and cement, and the hydration mechanism of cementitious materials with 5%, 10%, and 20% ASR was studied. The XRD and SEM results showed that the main hydration products of ASR-cement composite cementitious materials were an amorphous C-S-H gel, hexagonal plate-like Ca(OH)2 (CH), and regular hexagonal plate-like Friedel’s salt (FS). The addition of ASR increased the heat of hydration of the cementitious material, which increased upon increasing the ASR content. The addition of ASR also reduced the cumulative pore volume of the hardened paste, which displayed the optimal pore structure when the ASR content was 5%. In addition, ASR shortened the setting time compared with the cement group, and the final setting times of the pastes with 5%, 10%, and 20% ASR were 30 min, 45 min, and 70 min shorter, respectively. When the ASR content did not exceed 10%, the 3-day compressive strength of the mortar was significantly improved, but the 28-day compressive strength was worse. Finally, the hydration mechanism and potential applications of the cementitious material are discussed. The results of this paper promote the use of ASR in building materials to reduce CO2 emissions in the cement industry.

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Properties of Cementitious Materials with Recycled Aggregate and Powder Both from Clay Brick Waste

Buildings ◽

10.3390/buildings11030119 ◽

2021 ◽

Vol 11 (3) ◽

pp. 119

Author(s):

Huixia Wu ◽

Jianzhuang Xiao ◽

Chaofeng Liang ◽

Zhiming Ma

Keyword(s):

Mechanical Strength ◽

Water Transport ◽

Setting Time ◽

Drying Shrinkage ◽

Cementitious Materials ◽

Construction And Demolition Waste ◽

Recycled Aggregate ◽

Chloride Ingress ◽

Clay Brick ◽

Demolition Waste

The utilization of recycled brick aggregate (RBA) and recycled brick powder (RBP) in cementitious materials helps the reclamation of clay brick waste in construction and demolition waste. This work studied the properties of cementitious materials with RBA as aggregate and RBP as supplementary cementitious material. The RBA has lower apparent density and higher water absorption than natural aggregate, and RBP with an irregular micro-structure contains high content of silicon and aluminum oxides and possesses excellent pozzolanic activity. Incorporating RBP decreases the fluidity and increases the setting time, but the incorporated RBP improves the pore structure and decreases the average pore diameter of cementitious materials, thereby decreasing the permeability. Utilizing RBA increases the drying shrinkage, while the incorporated RBP decreases the drying shrinkage of cementitious materials; the mortar with 50% RBA and 30% RBP has the lower drying shrinkage than the common mortar without RBA and RBP. Incorporating RBA and high-volume RBP decreases the mechanical strength, while there is no obvious decrease in the mechanical strength for the mortar with 50% RBA and 30% RBP. Moreover, the flexural strength to compressive strength ratio increases with RBA and RBP incorporating. Utilizing RBA increases the water transport, while the water transport properties decrease with the RBP incorporation; incorporating appropriate content of RBA and RBP can obtain the cementitious materials with low permeability. Particularly, a significant decrease in chloride ingress occurs with the substitution of RBP.

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Construction and Demolition Waste (CDW) Recycling—As Both Binder and Aggregates—In Alkali-Activated Materials: A Novel Re-Use Concept

Sustainability ◽

10.3390/su12145775 ◽

2020 ◽

Vol 12 (14) ◽

pp. 5775 ◽

Cited By ~ 1

Author(s):

Rafael A. Robayo-Salazar ◽

William Valencia-Saavedra ◽

Ruby Mejía de Gutiérrez

Keyword(s):

Compressive Strength ◽

Portland Cement ◽

Circular Economy ◽

Room Temperature ◽

Heat Of Hydration ◽

Construction And Demolition Waste ◽

Demolition Waste ◽

High Class ◽

Construction And Demolition Wastes ◽

Alkali Activated

This article demonstrates the possibility of producing alkali-activated materials (AAM) from a mixture of mechanically processed concrete, ceramic, masonry, and mortar wastes, as a sustainable alternative for recycling construction and demolition wastes (CDWs) under real conditions. The addition of 10% Portland cement allowed the materials to cure at room temperature (25 °C). CDW binder achieved a compressive strength of up to 43.9 MPa and it was classified as a general use and low heat of hydration cement according to ASTM C1157. The concrete produced with this cement and the crushed aggregates also from CDW reported a compressive strength of 33.9 MPa at 28 days of curing and it was possible to produce a high-class structural block with 26.1 MPa according to ASTM C90. These results are considered one option in making full use of CDWs as binder and aggregates, using alkaline activation technology thereby meeting the zero-waste objective within the concept of the circular economy.

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Effect of Waste Glass on the Properties and Microstructure of Magnesium Potassium Phosphate Cement

Materials ◽

10.3390/ma14082073 ◽

2021 ◽

Vol 14 (8) ◽

pp. 2073

Author(s):

Qiubai Deng ◽

Zhenyu Lai ◽

Rui Xiao ◽

Jie Wu ◽

Mengliang Liu ◽

...

Keyword(s):

Compressive Strength ◽

Glass Powder ◽

Setting Time ◽

Potassium Phosphate ◽

Heat Of Hydration ◽

Waste Glass ◽

Hydration Heat ◽

Magnesium Potassium Phosphate Cement ◽

The Matrix ◽

Powder Content

Waste glass is a bulk solid waste, and its utilization is of great consequence for environmental protection; the application of waste glass to magnesium phosphate cement can also play a prominent role in its recycling. The purpose of this study is to evaluate the effect of glass powder (GP) on the mechanical and working properties of magnesium potassium phosphate cement (MKPC). Moreover, a 40mm × 40mm × 40mm mold was used in this experiment, the workability, setting time, strength, hydration heat release, porosity, and microstructure of the specimens were evaluated. The results indicated that the addition of glass powder prolonged the setting time of MKPC, reduced the workability of the matrix, and effectively lowered the hydration heat of the MKPC. Compared to an M/P ratio (MgO/KH2PO4 mass ratio) of 1:1, the workability of the MKPC with M/P ratios of 2:1 and 3:1 was reduced by 1% and 2.1%, respectively, and the peak hydration temperatures were reduced by 0.5% and 14.6%, respectively. The compressive strength of MKPC increased with an increase in the glass powder content at the M/P ratio of 1:1, and the addition of glass powder reduced the porosity of the matrix, effectively increased the yield of struvite-K, and affected the morphology of the hydration products. With an increase in the M/P ratio, the struvite-K content decreased, many tiny pores were more prevalent on the surface of the matrix, and the bonding integrity between the MKPC was weakened, thereby reducing the compressive strength of the matrix. At less than 40 wt.% glass powder content, the performance of MKPC improved at an M/P ratio of 1:1. In general, the addition of glass powders improved the mechanical properties of MKPC and reduced the heat of hydration.

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Cement-Based Renders Manufactured with Phase-Change Materials: Applications and Feasibility

Advances in Materials Science and Engineering ◽

10.1155/2016/7254823 ◽

2016 ◽

Vol 2016 ◽

pp. 1-6 ◽

Cited By ~ 10

Author(s):

Luigi Coppola ◽

Denny Coffetti ◽

Sergio Lorenzi

Keyword(s):

Compressive Strength ◽

Phase Change ◽

Phase Change Materials ◽

Residential Buildings ◽

Setting Time ◽

Drying Shrinkage ◽

Hydration Kinetics ◽

Mechanical Performances ◽

Entrapped Air ◽

Kinetics Of

The paper focuses on the evaluation of the rheological and mechanical performances of cement-based renders manufactured with phase-change materials (PCM) in form of microencapsulated paraffin for innovative and ecofriendly residential buildings. Specifically, cement-based renders were manufactured by incorporating different amount of paraffin microcapsules—ranging from 5% to 20% by weight with respect to binder. Specific mass, entrained or entrapped air, and setting time were evaluated on fresh mortars. Compressive strength was measured over time to evaluate the effect of the PCM addition on the hydration kinetics of cement. Drying shrinkage was also evaluated. Experimental results confirmed that the compressive strength decreases as the amount of PCM increases. Furthermore, the higher the PCM content, the higher the drying shrinkage. The results confirm the possibility of manufacturing cement-based renders containing up to 20% by weight of PCM microcapsules with respect to binder.

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The Effect of Substituting Rdf on the Physical and Environmental Properties of Coal Fly Ash

MRS Proceedings ◽

10.1557/proc-136-223 ◽

1988 ◽

Vol 136 ◽

Author(s):

Ashaari B. Mohamad ◽

David L. Gress

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Physical Properties ◽

Activity Index ◽

Coal Fly Ash ◽

Pozzolanic Activity ◽

Portland Cement Concrete ◽

Fly Ash Concrete ◽

Refuse Derived Fuel ◽

Cadmium And Lead

ABSTRACTRefuse-derived-fuel (RDF) consisting mainly of waste paper and plastics is a viable fuel source for the production of power. An experimental test burn partially substituting coal with RDF was undertaken by the Public Service of New Hampshire at the Merrimack Power Station.Five percent and ten percent RDF were substituted, on a BTU basis, for coal in the test bums. The chemical and physical properties of the resulting fly ash were determined. Twelve test burn days were run with 4 days of 5% RDF and 8 days of 10% RDF. Emphasis was placed on investigating the effect of the RDF fly ash on Portland cement concrete.Most of the chemical and physical properties of the coal-RDF fly ash were found to be comparable with ordinary coal fly ash except for the amount of cadmium and lead, the pozzolanic activity index and the compressive strength of fly ash concrete. Cadmium and lead were at average levels of 5.1 ppm and 102.6 ppm for the 5% RDF, and 7.8 ppm and 198.3 ppm for the 10% RDF, respectively. Although the pozzolanic activity index of coal-RDF fly ash increases over normal coal fly ash, preliminary results show that the 28-day compressive strength of concrete with direct replacement of cement and sand decreases by up to 30%. Leaching tests on crushed concrete were conducted to evaluate the environmental effect of acid rain.

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Investigation on Calcined Magnesium-Based Mineral Powder and Its Behavior as Alternative Binder

Advances in Materials Science and Engineering ◽

10.1155/2020/2963529 ◽

2020 ◽

Vol 2020 ◽

pp. 1-7

Author(s):

G. Sugila Devi ◽

K. Sudalaimani

Keyword(s):

Ph Value ◽

Sodium Tripolyphosphate ◽

Setting Time ◽

Drying Shrinkage ◽

Xrd Analysis ◽

Sem Analysis ◽

Heat Of Hydration ◽

Structural Development ◽

Initial Setting Time ◽

Initial Setting

This paper investigates the behavior of calcined powder made of natural magnesite and natural steatite. The magnesite and steatite are made into a powder of ratio 3 : 1 by weight proportion, and the combination is thermally decomposed at a temperature of 1200° Celsius. The calcined powder along with and without Sodium Tripolyphosphate (STPP) salt is tested for its microscopic structural development, consistency, initial setting time, final setting time, and heat of hydration. The powder is made into paste with water/powder ratio as 0.25 and the hardened samples are tested for its compressive strength, drying shrinkage, pH value, SEM analysis, and XRD analysis. The results show that adding phosphate salt increases the hydration process, setting time, and strength aspects. The test samples are found with hydration products such as magnesium hydroxide and struvite. Thus, the present work shows that natural metamorphic magnesite and natural metamorphic steatite can be the potential alternative resource for the production of magnesium-based binder.

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Feasibility and Characterization Mortar Blended with High-Amount Basic Oxygen Furnace Slag

Materials ◽

10.3390/ma12010006 ◽

2018 ◽

Vol 12 (1) ◽

pp. 6 ◽

Cited By ~ 1

Author(s):

Wei-Ting Lin ◽

Chia-Jung Tsai ◽

Jie Chen ◽

Weidong Liu

Keyword(s):

Steel Industry ◽

Setting Time ◽

Basic Oxygen Furnace ◽

Cementitious Material ◽

Partial Replacement ◽

Supplementary Cementitious Material ◽

Basic Oxygen ◽

Basic Oxygen Furnace Slag ◽

Furnace Slag ◽

Weight Proportion

Basic oxygen furnace slag (BOFS) was ground to three levels of fineness as a replacement for cement at weight proportions of 10, 30, 50, and 70 wt.%. Fineness and weight proportion were shown to have significant effects on the flowability and setting time of the mortars. The expansion of BOFS mortars increased with an increase in the proportion of cement replaced, thereby exacerbating the effects of cracking. Optimal mechanical properties were achieved when 10 wt.% of the cement was replaced using BOFS with fineness of 10,000 cm2/g. The compressive strength of BOFS mortar is similar to that of ordinary Portland mortar, which makes BOFS suitable for the partial replacement of cement as a supplementary cementitious material. Scanning electron microscopy results revealed that the reaction of CaO with H2O results in the formation of C–S–H colloids, whereas the reaction of SiO2 with Al2O3 produces C–A–S–H colloids. The use of BOFS as a partial replacement for Portland cement could make a tremendous contribution to the steel industry and help to lower CO2 emissions.

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