This study evaluates the use of large amounts of fine powders (fillers) derived from a Colombian volcanic material into the production of selfcompacting concrete (SCC) for lower strength applications. The effects on SCC properties were studied with the incorporation of up to 50% of volcanic material of Tolima (MVT) as a partial substitute of the total weight of Portland cement. The workability was determined through slump flow, Vfunnel, and Lbox test. The compressive strength results were analyzed statistically by MINITAB. These demonstrated that 30% (by total weight of cementitious material) was the maximum allowable percentage of MVT to be used in the production of SCCs. Based on this, mechanical and permeability properties of SCC MVT 30% were evaluated at 28, 90 y 360 curing days. SCC MVT 30% exhibited compressive strength of 21 and 27 MPa after 28 and 360 days of curing, respectively.
Selfcompacting concrete (SCC) has been gaining popularity in the construction industry in recent years because of its numerous advantages over the conventional concrete. Most important advantages of the SCC include a shorter construction time, improved conditions for workers because mechanical vibration is not necessary, and its easier application in complex architectural designs and densely reinforced structures (
Volcanic materials are formed during volcanic eruptions, and their vitreous state depends on the magma composition and the solidification process (
Type I Portland cement with a particle size of 22 μm was used for this study, and it met the specifications of the Colombian standard NTC 321. A river sand was used as fine aggregate and limestone crusher with a maximum nominal size of 12.7 mm was used as coarse aggregate. The bulk densities of the aggregates were 2,581 kg/m^{3} and 2,544 kg/m^{3}, and their water absorptions were 1.89% and 2.01%, respectively. A latest generation superplasticizer (SP) was utilized, which meets the requirements of ASTM C494 (
The volcanic material was originated in the
Chemical and physical properties of Portland cement and volcanic material from the Tolima volcano (MVT)
Type I Portland cement  MVT  



SiO_{2}  20.73  64.36 
Fe_{2}O_{3}  5.63  4.92 
Al_{2}O_{3}  4.54  15.90 
CaO  52.69  4.71 
Na_{2}O  0.15  5.38 
MgO  2.24  1.80 
TiO_{2}  0.24  0.54 
P_{2}O_{5}  0.14  0.17 
K_{2}O  0.41  1.49 
SO_{3}  3.14   
SrO  0.16   
Mn_{2}O_{3}  0.06   
Cr_{2}O_{3}  0.03   
ZnO  0.01   
Zr    0.01 
MnO    0.09 
Zn    0.01 
Sr    0.09 
Ba    0.08 
LOI  9.85  0.40 
Specific Gravity (kg/m^{3})  3100  2090 
Mean particle size(μm)  22.00  20.20 
On the other hand, the loss on ignition and specific gravity of MVT are 0.4% and 2,090 kg/m^{3}, respectively. Earlier studies on characterization (
Petrographic thin sections of Tolima volcanic material.
Xray diffraction patterns of Tolima volcanic materials.
Particle size distribution of Tolima volcanic material and Portland cement.
SEM microimages of Tolima volcanic materials at magnification: a) 1000X y b) 6000X.
An extreme vertices design of mixtures experiments was used in order to evaluate the effect of different mass percentages of MVT addition in SCC and to find the optimal proportion of incorporation that ensured adequate properties in fresh and hardened states. The response variable was the development of compressive strength over 28day curing time. The tests were performed and randomized using the MINITAB 16 software package and the treatments are presented in
Optimization treatments of the proportions of MVT with respect to Portland cement content
StdOrder  RunOrder  PtType  Blocks  MVT  Type I Portland Cement 

5  1  −1  1  0.43  0.57 
6  2  0  1  0.35  0.65 
7  3  0  1  0.35  0.65 
3  4  0  1  0.35  0.65 
4  5  −1  1  0.28  0.72 
2  6  1  1  0.50  0.50 
1  7  1  1  0.20  0.80 
The SCCs mixture proportions are presented in
Proportions of the selfcompacting concretes
SCC mixtures  W/C*  Water (kg/m^{3})  Cement (kg/m^{3})  Volcanic material (MVT)  Aggregates (kg/m^{3})  




kg/m^{3}  %  Sand  Gravel  %SP+  


REFERENCE  0.47  226  480  0  0  950  633  0.55 


MVT 20%  0.47  226  384  96  20  950  633  0.55 
MVT 28%  0.47  226  346  134  28  950  633  0.55 
MVT 35%  0.47  226  312  168  35  950  633  0.55 
MVT 42%  0.47  226  278  202  42  950  633  0.6 
MVT 50%  0.47  226  240  240  50  950  633  0.6 
After preparing the SCC mixtures as per experimental design, their fresh state properties, such as the filling capacity, passing ability, and resistance to segregation, were evaluated by slump flow, V funnel and L box tests, respectively according to the procedures and ranges established by the European specifications for SCC presented in
Specifications of the European guidelines for selfcompacting concrete.
Test methods  Unit  European guidelines values  

Filling capacity  SF1 class slump flow  mm  550–650 
SF2 class slump flow  mm  660–750  
SF3 class slump flow  mm  760–850  
T50 VF1  s  <2  
T50 VF2  s  >2  
VF1 class V funnel  s  ≤8  
VF2 class V funnel  s  sep25  
Passing ability  PA1 class L box  (h_{2}/h_{1})  ≥0.80 with 2 bars 
PA2 class L box  (h_{2}/h_{1})  ≥0.80 with 3 bars 
Fresh state properties of selfcompacting concretes with added MVT.
The compressive strength tests results were analyzed mathematically with the MINITAB 16 program. A quadratic regression model (Eq. [
Where
The analysis of variance (ANOVA) obtained for compressive strength (p value, coefficient of multiple determination R^{2} and adjusted coefficient of multiple determination,
The optimization plot of
Optimization of the proportions of MVT in selfcompacting concretes in terms of compressive strength after 28 curing days.
Mixture proportions of selfcompacting concrete with 30% MVT (SCC MVT 30%)
SCC mixture  W/C*  Water (kg/m^{3})  Cement (kg/m^{3})  Volcanic material (MVT)  Aggregates (kg/m^{3})  

kg/m^{3}  %  Sand  Gravel  %SP+  
MVT 30%  0.47  226  336  144  30  950  633  0.55 
C*= Cement mixture (Ordinary Portland cement + MVT).
Comparison of the fresh state properties of SCC MVT 30% and SCC of reference.
According to the classification proposed by the European guidelines for SCC and considering the results obtained from fresh properties of SCCs (
The mechanical properties of reference SCC and SCC MVT 30% at different curing times of up to 360 days are presented in
Mechanical properties of SCC MVT 30% and Reference SCC: a) Compressive strength, b) Tensile strength and c) Flexural strength.
Regarding permeability properties presented in
Permeability properties of SCC MVT 30% and SCC of reference
SCC Reference  SCC MVT 30%  

28 days  90 days  360 days  28 days  90 days  360 days  


Apparent Density (kg/m^{3})  2630  2718  2642  2698  2771  2651 
Volume of permeable voids (%)  14.62  15.43  17.94  21.44  22.99  17.01 


K (kg/m^{2}s^{1/2})  0.019  0.017  0.016  0.022  0.020  0.019 
m (s/m^{2}) x 10^{7}  5.40  5.45  6.29  3.14  3.32  4.62 
S (m/s^{1/2}) x 10^{−4}  1.36  1.35  1.26  1.78  1.74  1.47 
Effective Porosity Ɛ_{0} (%)  14.04  12.86  11.53  12.53  12.8  13.17 
This article describes the development of a selfcompacting concrete (SCC) of lower strength by incorporating a volcanic material (MVT) filler as replacement for Portland cement type I. Considering the results of fresh and hardened state properties, the following conclusions were derived:
All SCCs with MVT presented suitable properties according to the European guidelines. It was observed that the MVT has a fluidizing effect on SCC up to a proportion of 28% by weight of cementitious material. SCC MVT 20% and SCC MVT 28% mixtures showed the best workability/stability characteristics without exhibiting segregation or bleeding.
The experimental results on mix designs showed that the compressive strength of SCC decreased with the incorporation of MVT. However, the analysis of the experimental design indicated that MVT can be used to produce SCC in proportions from 20% to 30% as a replacement for type I Portland cement at a composite desirability of 1. Based on this, it was decided to use maximum content of MVT (30%) to evaluate the effect of this filler on the rheological, mechanical and durability properties of SCCs. According to the fresh state properties, SCC MVT 30% exhibited appropriate characteristics (good fluidity and passing ability) to be used in congested structures and structures with complex shapes.
Compressive strengths of 21 MPa and 27 MPa were obtained at 28 and 360 curing days, respectively with the incorporation of 30% MVT (as replacement of cement) in the SCC production with similar permeability properties compared to reference SCC (0% MVT). These findings showed the viability of producing MVT based SCCs for applications such as some precast structures where high strength is not necessary. Additionally, the use of 30% MVT as a filler permits the production of environmentally friendly and low cost SCCs. The use of MVT as an alternative filler in the SCC production will have a positive impact in concrete industries, considering the abundant volcanic regions around the world.
Authors would like to thank Universidad del Valle (Colombia) for its support for the development of this project. In particular, in this publication, partial results from the research project “Self–compacting concrete with volcanic materials”, internal code 2785, supported by Universidad del Valle, Internal Call. We also acknowledge the donations of volcanic materials by the company CEMEX and Administrative Department for Science and Technology (COLCIENCIASCOLOMBIA) and their National Doctorates program for providing support. Also, the support given by the Centro de Excelencia en Nuevos Materiales (CENM) to the Grupo de Materiales Compuestos is also acknowledged.