EPS concrete was produced by mixing the expanded polystyrene spheres (EPS) and polymer emulsion and thickener to the matrix concrete, and this concrete had good vibration energy absorption characteristics. Based on the experimental data obtained on EPS volume ratio of 0%, 20%, 30%, and 40% by replacing matrix or coarse aggregate, the two design styles had nearly the same compressive strength. By applying frequency of 5 Hz, 50000 or 100000 times, 40 KN, 50 KN, and 60 KN cyclic loading, it is shown that the higher the inclusion size was, the lower the compressive strength of the EPS concrete would be; the larger the applying dynamic cyclic load was, the more obvious the compressive strength changing would be. Meanwhile, the strength of EPS concrete had no evident change after durability test. The results of this research had practical significance on using EPS concrete in some longterm cyclic dynamic load engineering.
Because the expanded polystyrene (EPS) light weight concrete has the characteristics of lightweight, energy absorption, and heat preservation, it is used in many specific construction industries like high rise buildings, floating marine platforms, and largesized and longspan concrete [
In 1970s, Cook [
EPS concrete has been considered as an energyabsorbing material for the protection of buried military structure and some specific constructions which suffer longterm cyclic loading. Meanwhile, it has requirements for strength and durability of EPS concrete. The main purpose of this paper is to quantify the influence of the EPS concrete inclusion size on compressive strength, improving the strength and the workability of the EPS concrete by mixing three admixtures. The durability of the EPS concrete was obtained by making comparison between specimen before and after applying cyclic load of 40 KN, 50 KN, and 60 KN for 50000 or 10000 times.
The test specimens were made with the same type as that used for very high strength concrete, and the EPS particle took the place of part of the concrete or coarse aggregate.
Expanded polystyrene spheres.
There are two ways to approach this issue: one is to increase the bond action between the EPS particles and aggregates by transforming the EPS particles from hydrophobic material to hydrophilic material and the other is to improve the viscosity of the EPS concrete. In order to improve the compressive strength of the EPS concrete as much as possible, the specimen was made by adopting both methods. Polymer emulsion was mixed in the mixture to increase the viscidity; the relationship between compressive strength and mixing ratio is shown in Figure
The relationship between compressive strength and polymer emulsion mixing ratio.
The relationship between compressive strength and hydroxypropyl cellulose mixing ratio.
Cubes of 100 mm size of EPS concrete were used for studying the compressive strength after being stored in laboratory conditions for 28 days. Watercement ratio is an important index to influence the compressive strength. The relationship between watercement ratio and compressive strength is shown in Figure
The influence of the watercement ratio.
In order to observe the influence of the EPS particle volume ratio on the compressive strength, various densities of the EPS concrete specimens were made according to Table
Proportion of EPS concrete mixes.
EPS volume ratio%  Design type  Water/ 
Cement 
River sand 
Gravel 
Water 
Silica fume 
Superplasticizer 
Polymer emulsion 
hydroxypropyl cellulose 

0  No replacing  32  538  542  1152  172  26.9  8.07  8.07  2.69 


0.2  Replace the concrete  32  430  434  922  138  21.52  6.456  6.456  2.152 


0.2  Replace the gravel only  32  538  542  662  172  26.9  8.07  8.07  2.69 


0.3  Replace the concrete  32  375  380  808  120  18.75  5.625  5.625  1.875 


0.3  Replace the gravel only  32  538  542  662  172  26.9  8.07  8.07  2.69 


0.4  Replace the concrete  32  323  325  691  103  16.14  4.842  4.842  1.614 


0.4  Replace the gravel only  32  538  542  172  172  26.9  8.07  8.07  2.69 
The EPS volume ratio
Three specimens were made according to each design style and each value was reported because porosity and compressive strength of the specimen vary slightly. The effect of porosity on compressive strength of EPS lightweight concrete is shown in Figures
The variation of compressive strength of EPS particles replacing concrete with porosity.
The variation of compressive strength of EPS particles replacing coarse aggregate with porosity.
The minimum and maximum compressive strength of EPS concrete with the design style of EPS particles replacing concrete at the age of 28 days were 18.05 and 40.31 MPa; meanwhile, the minimum and maximum compressive strength were 16.23 and 40.07 MPa following the design style of EPS particles replacing coarse aggregate from Figures
According to the test value, the compressive strength of the two design styles was basically coinciding, but the porosity of the EPS concrete was different from Figures
Through exponential fit analysis, the empirical relations obtained can be written as
Failure mode of the EPS concrete with different EPS particles volume ratio.
EPS concrete has the characteristics of vibration resistance and energy absorption, which can be used in civil construction based on cycle loading to reduce vibration of system. However, it has great significance to test the durability of EPS concrete with vibration property since vibration load infliction often goes with the characteristic of low durability. This paper qualitatively analyzes the influence of EPS volume ratio, vibration cyclic times, and vibration load on EPS concrete durability by cycle loading test.
Cyclic dynamic vibration test used a 370.50 MTS electrohydraulic servo fatigue test system shown in Figure
MTS 370.50 dynamic test system.
After 50 thousand cyclic loading tests, the concrete would be in strength test; the value of the compressive strength before and after cyclic loading is shown in Figures
Later strength of 40 KN 50000time cyclic loading.
Later strength of 50 KN 50000time cyclic loading.
Later strength of 60 KN 50000time cyclic loading.
The compressive strength of concrete without EPS particles decreased to different degree after durability test and the greater the cyclic loading applied, the more obvious the reduction of concrete strength. The compressive strength of 20% EPS particles volume ratio concrete (20% EPS concrete) was less than before, while the compressive strength of 30% and 40% EPS concrete are varying degrees of increase when applying 40 KN cyclic load, mainly because cyclic loading led to EPS particles compression and the compaction of EPS concrete when applying load was small; therefore, the compressive strength of 30% and 40% EPS concrete was greater than before durability test. With applying load from 40 KN to 50 KN and finally to 60 KN, the influence of cyclic loading on durability of EPS concrete was becoming more and more obvious; meanwhile, the bigger the EPS particles volume ratio was, the smaller the compressive strength change after 50000 cyclic loading would be.
Because 100000time cyclic dynamic test costs long time, the research took EPS concrete of particles volume ratio of 0% and 30% as an example by applying 50 KN sinusoidal cyclic loading 100000 times on EPS concrete; the compressive strength before and after durability test is as shown in Figure
Later strength of 50 KN 100000time cyclic loading.
The change of compressive strength of the matrix was obvious after 100000 times of dynamic vibration loading as is shown in Figure
EPS concrete has the advantages of small density, thermal insulation, and good seismic performance. So it is of great significance on the study of modern structural materials and practical engineering to research new concrete materials. The experimental investigations were conducted on three types of EPS concrete having EPS concrete of particles volume ratio ranging from 0% to 40%, with a view to confirming the presence of an intrinsic particle content effect on the EPS concrete compressive strength and durability. The conclusions are drawn as follows.
In order to increase the compressive strength the polymer emulsion is mixing in the concrete grout which would bound other mixtures together, and the relationship between its mixing ratio and compressive strength is discussed. The hydroxypropyl cellulose is mixed in the EPS concrete for improving the workability of the grout and the influence of its mixing ratio on the concrete compressive strength is studied.
The compressive strength of two types of EPS concrete in which concrete is replaced or only gravel replaced by EPS particles was basically identical; the result showed that the compressive strength of the two design styles was basically coinciding. The compressive strength of EPS concrete decreased obviously with the increase of EPS particles volume ratio; the reduction curve was similar to exponential type curve.
The value of applying dynamic cyclic load had great effect on the compressive strength after durability test. The compressive strength of EPS concrete of particles volume ratio of 40% was increased after applying 40 KN and 50 KN cyclic dynamic load, and the other ratio of EPS particles volume concrete was reduced after durability test; meanwhile, the degree of compressive strength reduction was inversely proportional to EPS particles volume ratio. Also, the bigger the applying dynamic cyclic load was, the bigger the gap of compressive strength between before and after durability test would be. The compressive strength of EPS concrete of particles volume ratio of 0% and 30% would fall when dynamic cyclic load is applied 100000 times, and the reduction of matrix compressive strength was much more bigger than EPS concrete particles volume ratio of 30% compared with applying dynamic vibration load 50000 times.
Through the results from the designed durability test, it proved that the EPS lightweight concrete has good durability and it has a very good use in practical engineering which has certain seismic requirements and applied cyclic load.
The authors declare that there is no conflict of interests regarding the publication of this paper.