scholarly journals Production of concrete compatible biogranules for self-healing concrete applications

2019 ◽  
Vol 289 ◽  
pp. 01002 ◽  
Author(s):  
Merve Sonmez ◽  
Yusuf Cagatay Ersan
Keyword(s):  
Calcium Nitrate ◽  
Nutrient Content ◽  
Early Age ◽  
Self Healing ◽  
Fresh Properties ◽  
Microbial Cultures ◽  
Production Strategy ◽  
Rebar Corrosion ◽  
Cost Efficient ◽  
Calcium Formate

Recently, cost-efficient nitrate reducing biogranules were suggested as an alternative to axenic microbial cultures for development of microbial self-healing concrete. In a marine environment, biogranule containing microbial self-healing concrete showed simultaneous self-healing of cracks and immunisation against rebar corrosion. Yet, information about the production strategy of these biogranules and their compatibility with a mortar matrix is limited. This study presents the production of biogranules and their compatibility with mortar specimens when incorporated at dosages between 0.36% to 4.30% w/w cement (0.25% to 3% of bacteria w/w cement). In-house produced biogranules composed of 70% bacteria and 30% of minerals w/w of biogranule were used for the compatibility tests. In test mortars, calcium formate (CF) and calcium nitrate (CN) were used as regular nutrient admixtures, and nutrient content was set identical in every batch. Up to 2.9% incorporation, biogranules had no significant influence on the fresh properties of mortar. More than 2.9% incorporation caused poor workability and a 26% decrease in 3-Day compressive strength of biomortar specimens. Overall, the biogranules produced are compatible with a cementitious matrix up to 2.9% w/w cement, and even up to 3.6% if early age strength is not essential, which makes biogranules one of the most compatible microbial healing agents among the suggested agents in the literature.

scholarly journals Compatibility and Biomineralization Oriented Optimization of Nutrient Content in Nitrate-Reducing-Biogranules-Based Microbial Self-Healing Concrete

2021 ◽  
Vol 13 (16) ◽  
pp. 8990
Author(s):  
Beyza Kardogan ◽  
Kadir Sekercioglu ◽  
Yusuf Çagatay Erşan
Keyword(s):  
Microbial Activity ◽  
Dissolved Inorganic Carbon ◽  
Calcium Nitrate ◽  
Nutrient Content ◽  
Self Healing ◽  
Calcium Carbonate Precipitation ◽  
Precipitation Efficiency ◽  
Crack Repair ◽  
Calcium Formate

Microbially induced calcium carbonate precipitation (MICP) can be mentioned among the popular approaches to develop a self-healing concrete. The production of dissolved inorganic carbon through microbial activity is the main precursor for MICP in concrete and it is limited by the bioavailability of the nutrients. When nutrients are added to the mortar as admixtures, their bioavailability becomes more significant for crack repair because nutrients disperse in the mortar and considerable fraction stays far from a single crack. Therefore, the determination of bioavailability of nutrients and its variation with the initial nutrient content and crack age is essential to optimize a recipe for bacteria-based self-healing concrete. This study presents the optimum nutrient content defined for nitrate-reduction-based self-healing bioconcrete. In the tests, calcium nitrate (CN) and calcium formate (CF) were combined with a CF:CN w/w ratio of 2.50. Mortar properties and bioavailability of nutrients were analysed at different nutrient doses. Moreover, the bioavailability of nutrients at different crack ages changing between 3 and 56 days was monitored. Finally, resuscitation, microbial activity and the MICP performance of nitrate reducing biogranules were tested at defined nutrient bioavailabilties. The optimum nutrient content was determined as 7.00% (CF 5.00% and CN 2.00%). The leaching rates of formate ions were twice the leaching rate of the nitrate ions at similar initial concentrations, which led to a bioavailable HCOO−/NO3-N ratio of 23 g/g in cracked mortar. Under optimum nutrient conditions, the CaCO3 precipitation yield of nitrate reducing biogranules was recorded as 1.5 g CaCO3/g HCOO− which corresponded to 68% C precipitation efficiency.

scholarly journals Investigation of the Relationship between Compressive Strength and Hydrate Formation Behavior of Low-Temperature Cured Cement upon Addition of a Nitrite-Based Accelerator

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3936 ◽  
Author(s):  
Jihoon Kim ◽  
Daiki Honda ◽  
Heesup Choi ◽  
Yukio Hama
Keyword(s):  
Compressive Strength ◽  
Calcium Nitrate ◽  
Hydrate Formation ◽  
Strength Development ◽  
Early Age ◽  
Enhancement Effect ◽  
Freezing Damage ◽  
Formation Behavior ◽  
Relative Production ◽  
The Relationship

When concrete is used for construction in cold-temperature regions, cold-resistant accelerators based on calcium nitrite (Ca(NO2)2) and calcium nitrate (Ca(NO3)2) are added to prevent early freezing damage. Although cold-resistant accelerators increase the early compressive strength and prevent early freezing damage by promoting cement hydration, the strength enhancement effect owing to the formation of such hydrates has not been evaluated quantitatively thus far. This study covers various types of analysis to understand the relationship between cement hydrate formation behavior and strength development upon the addition of varying amounts of nitrite-based accelerator. We find that the early compressive strength is enhanced by the addition of nitrite-based accelerator via the promotion of the relative production of monosulfate and C-S-H in the early age. However, the development of compressive strength decreases with an increase in the curing age. Furthermore, we find that the promotion of hydration reactions at an early age with the addition of nitrite-based accelerator can affect the formation ratio of each hydrate at a late age. We believe our findings can significantly contribute to developments in concrete application and allied fields.

Self-healing of early-age cracks in cement mortars with artificial functional aggregates

2021 ◽  
Vol 272 ◽  
pp. 121846
Author(s):  
Mian Luo ◽  
Jingquan Bai ◽  
Kang Jing ◽  
Ziqi Ding ◽  
Dingyi Yang ◽  
...  
Keyword(s):  
Early Age ◽  
Self Healing ◽  
Cement Mortars

Effects of calcium formate on early-age strength and microstructure of high-volume fly ash cement systems

2021 ◽  
pp. 1-13
Author(s):  
Zhiyuan Zhou ◽  
Massoud Sofi ◽  
Aocheng Zhong ◽  
Amin Shahpasandi ◽  
Marvel Cham Sarabia ◽  
...  
Keyword(s):  
Fly Ash ◽  
High Volume ◽  
Early Age ◽  
High Volume Fly Ash ◽  
Calcium Formate

Single microcapsules containing epoxy healing agent used for development in the fabrication of cost efficient self-healing epoxy coating

2018 ◽  
Vol 114 ◽  
pp. 40-46 ◽  
Author(s):  
Fariba Safaei ◽  
Saied Nouri Khorasani ◽  
Hadi Rahnama ◽  
Rasoul Esmaeely Neisiany ◽  
Mohammad Sadegh Koochaki
Keyword(s):  
Epoxy Coating ◽  
Self Healing ◽  
Healing Agent ◽  
Cost Efficient

scholarly journals Application of Reproduction Biotechnology and Molecular Genetic to Improve Productivity of Local Pigs

2018 ◽  
Vol 27 (4) ◽  
pp. 177
Author(s):  
Bayu Dewantoro Putro Soewandi
Keyword(s):  
Marker Assisted Selection ◽  
Molecular Genetic ◽  
Productivity Index ◽  
Carcass Quality ◽  
Early Age ◽  
Breeding Scheme ◽  
Large Numbers ◽  
Size Number ◽  
Local Pigs ◽  
Cost Efficient

Low productivity in local pigs is due to the absence of breeding plan with mating arrangements. The main productivity variables used in breeding are litter size (number of piglets), weaning litter, number of teats, sow productivity index, growth rate, slaughter weight, and carcass quality. Selection to produce a new breed in breeding scheme should be conducted within five generations requiring large numbers of livestock, length period, and costly. Biotechnology reproduction and genetic molecular can be used to increase the value of the variables, to shorten interval generation, and cost efficient. This paper provides information on the use of reproduction biotechnology and molecular genetic from various sources and utilization of both technologies to increase local pig productivity. Reproductive biotechnology is useful in mating arrangement and molecular genetic using marker assisted selection (MAS) is able to determine superior pig since early age.

scholarly journals Studies of the influences of different N fertilizers and Microbion UNC bacterial fertilizer on the nutrient content of soil

2010 ◽  
pp. 134-140
Author(s):  
Andrea Balla Kovács ◽  
Anita Szabó ◽  
Emese Bartáné Szabó
Keyword(s):  
Ammonium Nitrate ◽  
Inorganic Nitrogen ◽  
Block Design ◽  
Calcium Nitrate ◽  
Nutrient Content ◽  
Nitrogen Fertilizers ◽  
Organic N ◽  
Total N ◽  
N Fertilizers ◽  
Soil Measurements

A field experiment was conducted to examine the effects of different nitrogen fertilizers in combination with bacterial fertilizer onnutrient uptake of horseradish and plant available nutrients of the soil. Three different N fertilizers, ammonium-nitrate, urea and calciumnitrate(116 kg ha-1 N) in combination with Microbion UNC bacterial fertilizer (2 kg ha-1) were applied as treatments in a randomizedcomplete block design in three replications. In this paper we presented the results of soil measurements. The soil of the experimental areawas chernozem with medium sufficiency level of N and P and poor level of K.Our main results:The amount of 0.01M CaCl2 soluble inorganic nitrogen fractions, NO3--N and NH4+-N and also the quantity of soluble organic-N werealmost the same in the soil. N fertilizers significantly increased all the soluble N fractions. The amount of NO3--N increased to the greatestextent and the increase of organic N was the slightest. We measured the largest CaCl2 soluble NO3- -N and total-N contents in the plotstreated with ammonium-nitrate, the largest NH4+-N in the plots treated with calcium-nitrate and the largest organic-N fraction in plotstreated with urea.Bacterial inoculation also increased both soluble inorganic nitrogen forms and also total-N content of soil compared to the control. Inthe case of combined (artificial and bacterial fertilizer) treatments we measured lower NO3--N, organic-N and total-N compared to thevalues of plots having only nitrogen fertilizer treatments. On the contrary in the plots with combined treatments the CaCl2 soluble NH4+-Ncontent of soil in more cases were higher than that of values with artificial fertilizer treatment.As a function of calcium-nitrate application increased AL-P2O5 and AL-K2O values were measured compared to control. MicrobionUNC supplement of calcium nitrate yielded also increase in AL-P2O5 and AL-K2O values, till then supplement of ammonium-nitrate fertilizeryielded a decrease in these values compared to the control.All nitrogen fertilizers resulted in a significant decrease in AL-Mg content of soil compared to the control. Nevertheless bacterialfertilizer increased AL-Mg values in any cases.

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